Higher nadir CD4+ T lymphocyte count (per 100 cells/mm3) was associated with significantly reduced hazard of tuberculosis (HR 0.79, 95 % CI 0.70–0.89), esophageal candidiasis (HR 0.74, 95 % CI 0.62–0.89), cerebral toxoplasmosis (HR 0.62, 95 % CI 0.48–0.81) and PCP (HR 0.58, 95 % CI 0.43–0.79). The gene discussed is CD4; the disease is tuberculosis.