The LSOCA study noted one incident case of CMV retinitis with a CD4 count in the 50–99 cells/mm3 range (incident rate, 0.18/100 person-years) and two cases in the higher than 100 cells/mm3 group (incident rate, 0.03/100 person-years).6 Again, it should be noted that these counts refer to the CD4 level at the visit immediately preceding their ophthalmic assessment and that all three cases had recorded levels lower than 50 cells/mm3 at some earlier point in their disease. The gene discussed is CD4; the disease is cytomegalovirus retinitis.