The ability for CD4 + effector T cells to produce TB antigen–specific cytokines was significantly increased at necropsy in the lungs of Erdman-infected NHPs, which experienced a significant increase in the proportion of CD4+ effector T cells that produced a cytokine, either IFN-γ, IL-17, or TNF-α, in response to stimulation with Mtb cell wall (Figure 3B). The gene discussed is CD4; the disease is tuberculosis.