Seay et al. found greater sleep disturbances were associated with lower CD4 counts.21 However, a South African cohort study established that poor sleep quality was associated with higher CD4 counts, when adjusting for depression severity, daytime sleepiness and pain.22 With regard to ART, a longitudinal prospective study examined sleep quality of HIV positive patients pre- and 1 year post-ART initiation. The gene discussed is CD4; the disease is depressive disorder.