Gene therapy can occur inside the body, but it can also be completed outside the body—with scientists treating cells in the lab, and then those corrected cells are transplanted back into the body.

Gene therapy treats a disease by editing the disease's underlying DNA, replacing it with a functional variant.

See this list of FDA-approved gene therapies, including offerings for inherited conditions as well as some forms of cancer.

Gene therapy, a hope of the Human Genome Project, has successfully treated a baby born with a rare urea cycle disorder that causes toxic ammonia level buildup.

A single-gene mutation in the FOXC2 gene gave actress Elizabeth Taylor two rows of eyelashes.

How personalized gene-editing saved a baby's life

KJ Muldoon had a 50% chance of surviving a genetic mutation until doctors developed a one-of-a-kind gene-editing therapy. In an interview with one of the researchers behind the treatment, learn what it will take to make personalized genetic medicine possible for everyone.

The 'Armamentarium' is a set of new gene therapy tools—including viruses that could shuttle therapies into the body—designed to fight brain diseases.

Scientists using gene therapy recently managed to regenerate retinal cells in the lab—a breakthrough for mammals that could potentially lead to future treatments for human retinal diseases.

Gene therapy is restoring hearing among kids with genetic deafness

Gene therapy for profound genetic deafness has been advancing in recent years, with multiple clinical trials enabling hearing at normal levels for the first time without hearing aids or cochlear implants. The therapies target hearing loss caused by mutations in the OTOF gene that codes for a protein called otoferlin. That protein normally plays a key role in relaying sound signals in synaptic transmission between the ear's inner hair cells and the auditory nerve.

In 2023, the FDA approved gene therapy for sickle cell disease, enabling one-time infusion bespoke treatments that use a patient's own stem cells to effectively cure a painful condition that disproportionately affects people of African American descent.

See how CAR-T cell therapy works to help fight cancer

Short for chimeric antigen receptor T-cell therapy, CAR-T Cell Therapy helps augment the body's own ability to attack cancer cells. It's a cell-based gene therapy that alters the genes in a person's T cells—which are a type of immune cell—to help them beat back cancerous growths.

A planned clinical trial to treat a rare lysosomal storage disorder in utero has buoyed hopes of providing prenatal gene therapies, but it was still awaiting FDA approval to begin enrolling patients as of May 2026.

Synthetic biology can prevent extinction by creating create disease-resilient plants and animals

Through gene editing and the deployment of artificial cells, scientists can leverage learnings from the genetic sequencing of animals with known resistances to protect endangered species. Gene editing of certain species, such as mosquitoes, can also reduce their ability to spread diseases like malaria between humans.

Genetic engineering will change everything forever

Designer babies, the end of diseases, genetically modified humans that never age. Outrageous things that used to be science fiction are suddenly becoming reality. As scientists increasingly understand how specific genes cause disease, the possibility of engineering our genes to not only "fix" problems but enhance our natural ability grows.

In 2026, the FDA proposed a novel approach to expedite reviews of gene therapies for patients with rare genetic disorders such as cystic fibrosis, potentially bypassing the need for years-long clinical trials if approved.

Recombinant DNA technology turns microorganisms into protein factories

Genes for molecules such as insulin can be inserted into loops of bacterial DNA called plasmids and reinserted into bacteria. Once placed in fermentation tanks, these bacteria use the gene to produce these molecules, which are then harvested and purified for eventual use.

Epigenetic editing—altering gene expression by removing or adding chemical groups on DNA—is making significant strides in the lab, even lowering cholesterol in monkey experiments by about 70%. (Free w/email.)

Genetic engineering has accelerated millennia of altering various crops' genes

Although farmers have long cross-bred crops to obtain plants with specific colors, sizes, and other characteristics, these processes took significant time. Today, genetic modification in agriculture involves scientists altering an organism's DNA for various purposes, including enhancing pathogen resistance, removing allergens, and delaying spoilage.

Synthetic biology transforms cells into custom DNA foundries

At companies like Ginkgo Bioworks, researchers are reprogramming cells to act as workshops that can create custom molecules, such as medicines and fertilizers, by stitching together DNA sequences—often in novel combinations—before inserting them into an organism's genome.

CRISPR allows scientists to cut out and replace faulty or unwanted DNA, which can help treat genetic disorders, such as sickle cell disease, and create genetically modified organisms, such as allergen-free foods.

Changing a single letter in DNA can permanently alter an organism

Genetic mutations occur when cells replicate, which requires a copy of DNA to be created, and involve substituting, deleting, or inserting letters in a cell's genetic code. Mutations can be caused by normal cellular processes, chemical exposure (e.g., carcinogens), or radiation and may result in genetic disorders or genetic variations that drive evolution.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

CRISPR is a gene-editing tool that lets scientists cut out and replace damaged DNA.

A first-of-its-kind clinical trial taps livers from gene-edited pigs to clean blood

The experimental dialysis-like treatment from United Therapeutics, eGenesis, and OrganOx, is designed to help people with liver failure. The therapy, which involves attaching the modified pig liver externally, filters a patient’s blood so their own livers can temporarily rest and perhaps heal.

Gene therapy for a rare type of deafness is allowing deaf children and adults to hear for the first time, according to research results reported in April 2026.

Teaching immune cells to fight cancer

CAR T-cell therapy is a type of immunotherapy, which involves strengthening the immune system to attack cancer cells. Patient T cells, which manage immune responses and are responsible for killing pathogen-infected cells, are collected and re-engineered to produce surface-level proteins called chimeric antigen receptors. These CARs, now able to bind to specific proteins on cancer cell surfaces, are multiplied into the millions and infused back into the patient.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

In vitro gametogenesis: using induced stem cells to fertilize eggs

Using stem cells from skin and mouth cells could save hopeful parents time and money and spare egg donors from significant amounts of discomfort throughout the process. There are potential consequences, not just for infertility treatment, but for the ability to create customized cells of any type.

Tumor genetic profiling can lead to targeted treatments

Genetic profiling of tumors—based on a sample from the tumor, a patient's blood, or both—can help clinicians determine if targeted therapies known to block the growth of certain types of tumors would be appropriate for specific patients.

A scientist successfully treated her own breast cancer by injecting the tumor with lab-grown viruses.

Why CAR-T therapy has become one of the main focus areas for autoimmune diseases

The therapy, originally targeting cancer, involves taking a patient's own T cells, genetically reprogramming them to recognize and attack a specific target and then infusing them back into patients. For autoimmune diseases, the therapy instead programs them to target immune cells that are causing problems, restoring immune system tolerance.

Gut bacteria are evolving and can acquire as many as 100 new genes per year, on average.

See how a novel gene editing technique called base editing can create changes in a single DNA base, using a more precise targeting approach than CRISPR-Cas9.

A new type of immunotherapy focuses on healthy cells hijacked by tumors

Purdue University scientists are at work on a new cancer treatment that attacks immune system cells that feed and protect cancer cells rather than attacking them. The immunotherapy process promises to become a universal treatment for solid tumors. Thus far, the treatment has been tested and shown to work on human tumor cells in the laboratory and animal models.

Genetic drug matching, called pharmacogenomics, can help avoid dangerous drug reactions

Certain gene variants can affect how quickly or slowly medications are broken down in the body, affecting drug effectiveness and the risk of drugs failing. Such testing is often not covered by insurance companies though research indicates if these tests were performed for more than six drugs across the US population, avoided ailments would likely climb into the hundreds of thousands. (Some users may encounter a paywall.)

Where do genes come from?

There are many more genes on Earth today than when microbial life first spawned on the planet about four billion years ago. Many of these newer genes grew from genetic mutations, misprints that slowly drift from the original blueprint via cellular division. If these mutations drift far enough, they can establish a new family of genes, though this process can take well over a million years.

How to turn any cell of the body into a stem cell

Scientists have developed techniques allowing them to 'reprogram' any cell in the body into an induced pluripotent stem (iPS) cell, which can be used to create either more stem cells or specialized cells for use in experimental medical treatments. This page gives readers a brief introduction to the history of iPS cells, what researchers are studying with iPS cells, and challenges associated with iPS research.

Stem cell therapies

Stem cells' special attributes interest researchers developing new therapeutic tools for a variety of health problems. Much of this research is done with support from the National Institutes of Health (NIH). This page offers a snapshot of research programs funded by the NIH and the health problems those programs focus on.

How medical robots could cure cancer

Medical robots are on the verge of being able to be injected into the body, where they will be responsible for semi-autonomous behavior, such as detecting cancer cells and distributing medication. This six-minute video dives into the science of these nanorobots, which are smaller than blood cells. Applications of these nanobots could range from disease discovery and condition monitoring to tissue repair and artificial blood delivery.

Research studies can be conducted inside or outside of living samples

While "in vitro" experiments occur outside living organisms for cost-effectiveness, "in vivo" experiments take place inside them, providing real-life insights at a higher cost and with increased ethical concerns. Alternatively, "in silico" methods use computational simulations.

Mitochondrial DNA swapping can occur before or after fertilization

Mitochondrial replacement therapy can be conducted with four different techniques, with varying genetic material transferred depending on the approach. Maternal spindle transfer, one common method, involves transplanting the nuclear DNA from a mother into an unfertilized egg from a donor. The donor egg is then fertilized and implanted into the mother's uterus using in vitro fertilization. Another major approach, pronuclear transfer, does the genetic swapping after the mother's egg has already been fertilized. This order of operations may be uncomfortable for some individuals, but the success rate with this technique is higher.

Explore different pig-to-human xenotransplantation possibilities, including using pig pancreatic cells for treating diabetes.

The first CRISPR-approved treatment was for sickle cell anemia in 2023

Victoria Gray was the first patient to receive a CRISPR-based therapy, which eliminated her symptoms and restored her health. The therapy's initial cost of $2.2M has kept it out of reach of many patients.

What is cancer bioengineering?

While new treatments for cancer are under continuous development, researchers are increasingly using engineering principles to find wholly new strategies to combat the disease. Directions include nanoparticle drug delivery, advanced imaging tools, developing new materials to interact with cells, tissue engineering, robotic surgeries, and more. Such interdisciplinary efforts are expected to unlock new tools and therapies beyond traditional drug formulation.

Somatic expansion, the lifelong growth of specific repeating DNA sequences, is being studied as a potential treatment target for Huntington's disease and other disorders.

While humans have been genetically modifying plants for millennia by selectively breeding organisms with certain traits, gene-editing tools like CRISPR have further enhanced plants, conferring resistance to drought, pests, and diseases.

The scientist that biohacked a buff frog

If a tree frog was injected with a DNA mixture containing follistatin, a gene that may influence muscle growth, would it become buff? Josiah Zayner hopes so. By learning how to biohack animals, he hopes people are one step closer to feeling more comfortable "whipping up DIY gene therapy."

Cells translate genetic information into proteins using RNA messengers

Genes are segments of DNA, each composed of a sequence of nitrogenous bases. Within the nucleus, these sequences are copied into a single strand of ribonucleic acid during transcription. This strand leaves the nucleus and is translated by ribosomes into a chain of amino acids that folds into a functional protein.

CRISPR can't fix faulty mitochondria

Gene editing via CRISPR could theoretically fix many issues in biology, but editing the mitochondrial genome has remained challenging. In recent years, there has been some progress reaching these cellular powerhouses. (Some users may experience a paywall.)

Restoring vision in impaired patients via CRISPR

Since CRISPR was revealed as a gene editing tool in 2012, it has been on an accelerated track to real-world applications. Among other clinical demonstrations, doctors have now injected a CRISPR treatment directly into eye cells, helping vision-impaired patients see shapes and colors again.

mRNA vaccines alter immune response, not DNA, to combat diseases like cancer.