Service related determinants of delayed ART initiation were: fears of ART drug toxicity (POR=2.19, p=0.03); being treated for TB first time (POR=2.23, p=0.05); having had a CD4 test done (POR=0.24, p=0.00); initially registered for HIV care outside Sanyati (POR=2.95, p=0.01); initially sought TB/HIV care outside public health sector (POR=2.88, p=0.001); staying more than 5 kilometers from health facility (POR=3.51, p=0.002); cost to reach ART initiating site more than US$1 (POR=1.91, p=0.05). The gene discussed is CD4; the disease is tuberculosis.