CD4 lymphocyte counts of 50 cells/μL or less have been clinically used to guide CMVR screening in HIV-positive and acquired immune deficiency syndrome patients, leading to rapid treatment and an improved prognosis for CMVR in these populations (Ford et al., 2013; Colby et al., 2014; Leenasirimakul et al., 2016). The gene discussed is CD4; the disease is AIDS.