No difference was found in the CD4 count, the CD4 nadir, the viral load, the number of months of HIV infection, and serum FSH (Table 2) between subjects with serum total T<300 ng/dL and those with normal serum total T. No substantial difference was found in the class of antiretroviral drugs used and in the time of exposure to the drugs (Table 2), except for the duration of exposure to PI (p<0.05), and NRTI (p<0.005), which resulted longer in patients with normal T than in patients with T deficiency (Table 2). The gene discussed is CD4; the disease is HIV infectious disease.