Cell culture using the TALEN showed that the technique achieved cleavage efficiency more than 50% to reproduce homozygous CCR5Δ32 mutations in CD4+-U87 cells with no selective pressure; the CCR5 to CCR5Δ32 recombination occurred in 8.8% in targeted cells, which were then resistant to HIV infection (29). Here, CD4 is linked to HIV infectious disease.