The hazard of bacterial pneumonia was higher when CD4 count was <200 cells/μL (HR: 2.98; CI: 1.80–4.94; P<0.001) or between 200 and 349/mm3 (HR: 1.98; CI: 1.25–3.15; P = 0.004) as compared when CD4 count ≥500 cells/μL. The gene discussed is CD4; the disease is bacterial pneumonia.