These include increased expression of Eomes and TOX as key features of exhausted T cells associated with disease severity in HIV infection while CD8+ T cells expressing lower levels of inhibitory receptors like PD-1 and higher levels of CD127, TCF1 and/or CXCR5 were associated with higher functionality, proliferation and better control of viral replication (129–131). This evidence concerns the gene CD8A and HIV infectious disease.