A wide range of risk factors associated with AZT-induced anemia have been reported in literature including older age, advanced stage of HIV infection, lower CD4 lymphocyte count, lower hemoglobin level at the time of starting AZT-containing regimen, female gender, patient's BMI and concomitant use of cotrimoxazole prophylaxis [4], [8], [14], [23], [24]. The gene discussed is CD4; the disease is HIV infectious disease.