Our findings suggest, that since TFV rapidly induces MIP3α and IL-8 secretion by macrophages, DCs and activated CD4+ T cells, it may increase susceptibility to HIV-1 infection by amplifying the presence of HIV-1 target cells at the genital mucosal, in which case timing of TFV application and sexual contact becomes a critical issue. The gene discussed is CD4; the disease is HIV-1 infection.