CD4 and viral infectious disease: These factors may include viral proteins/RNAs/miRNAs released from HIV reservoirs, CD4 T cell nadir, age, duration of viral infection, frequent hepatitis C virus (HCV), hepatitis B virus (HBV), cytomegalovirus (CMV), Epstein–Barr virus (EBV), tuberculosis (TB), and other pathogen coinfections, cell-secreted pro-inflammatory cytokines, endogenously generated reactive oxygen species (ROS), HIV-enhanced gut permeability or altered gut microbiota, ART regimens, associated malignancies, personal stresses, and social or environmental factors (14–18).