The cells in your body are not all the same. Each of your organs has cells with very different functions. For example, liver cells are top-notch secretors, as their job requires them to make and export many of the proteins in your blood. By contrast, muscle cells are tasked with facilitating the contractions that allow you to move.
The fact that cells are so specialized has implications for gene therapy, a way to treat genetic diseases by correcting the source of the error in a patient’s DNA. Health providers use a harmless viral or bacterial vector to carry a corrective gene into a patient’s cells, where the gene then directs the cell to produce the proteins necessary to treat the disease. Muscle cells are a common target because gene therapies injected into the muscle are more accessible than introduction into the body by other routes. But muscle cells may not produce the desired protein as efficiently as needed if the job the gene instructs it to do is very different from the one it specializes in.
