In contrast to p53, the mechanism of induction of KLF2 after HIV infection is not known, and the absence of KLF2 upregulation after treatment of primary CD4+ T cells with IFNα did not support the possibility that similar to p53, upregulation of KLF2 is induced by the innate immune response (Supplementary Fig. 2). This evidence concerns the gene CD4 and HIV infectious disease.