CD8A and HIV infectious disease: The transcriptional factor BATF is downstream of the PD-1 receptor signaling and play a key role in CD8+ T cell exhaustion and a recent study investigated primary HIV-specific T cells by silencing BATF expression and demonstrated that it augmented IL-2 production, suggesting that BATF may play an important role in impairment of CD4+ T cells in HIV infection [35,47].