In support of this, Lai et al report that patients with baseline CD4 cell count lower than 100 cells/mm3 were significantly associated with the presence of CMV retinitis (χ2-test, P=0.013).4 Gharai et al reviewed 199 eyes in HIV-infected patients and found that the median CD4 count of the patients with active CMV retinitis was 75 cells/mm3. The gene discussed is CD4; the disease is cytomegalovirus retinitis.