The inhibition of HIV infection did not result from cytotoxicity or inhibition of T cell activation by genistein; when resting CD4 T cells were similarly treated with genistein and activated with CD3/CD28 beads, we did not observe inhibition of T cells activation at all the dosages tested, as judged by the upregulation of the CD25 and CD69 surface receptors (Figure 1G). This evidence concerns the gene CD28 and HIV infectious disease.