Indeed, mucosal immunodeficiency begins in the early phase of HIV or SIV infection and is characterized by a profound and selective depletion of CD4+ T cells within days of infection [55] and preferential loss of IL-22 and IL-17 producing T cells [31], [56], impaired neutrophil recruitment and macrophage phagocytic function [41], and local mucosal inflammation [52], [57], [58]. The gene discussed is CD4; the disease is infection.