One problem in fighting AIDS has been the ability of the virus to become a living part of the body. When the infection begins, the AIDS virus enters white blood cells and intertwines its genes among the cell's own genes, forming a permanent infection. From its safe haven deep within the cells that normally would kill it, the AIDS virus can produce proteins needed to make new viruses. It is the production of virus proteins that kills the body's cells.

Bone marrow from the AIDS patient would then be removed and mixed with retroviruses carrying the artificial gene, which would infect the marrow cells in much the same way as does the AIDS virus. Once the retrovirus infects the cells, its anti-AIDS genes would be unpacked and integrated into the cell's genes.

The AIDS virus genes also make mRNAs. The anti-AIDS mRNA is complementary to the AIDS mRNA, just as the fuzzy side of Velcro is complementary to the prickly piece. When the two mRNA molecules encounter each other in the cell, they would stick together, much as two pieces of Velcro stick together.