Some specific HIV clinical care indicators used are: CD4 cell count, viral load test, non-detectable HIV viral load at 48 treatment weeks, Hepatitis C screening, Hepatitis B testing, Tuberculosis screening, Hepatitis B vaccination, PCP (pneumocystis jiroveci pneumonia) prophylaxis, adherence to ART, appropriately prescribed ART, and HIV-TB co-treatment. The gene discussed is CD4; the disease is hepatitis B virus infection.