Getting Genes Inside Cells

The system used to deliver the desired gene into the cells, called the gene therapy vector, may be a virus, a plasmid, or even just the naked DNA. The choice of vector is based on the difficulty of getting the gene into the cell, the amount of DNA the vector can carry, the size of the gene sequence needed to provide the correct protein, and the effects the vector may have on the body. Each type of vector has advantages and disadvantages. 

Viruses are very important as gene therapy vectors. Over the millennia of their existence, they have evolved to be very good at 

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