Prior studies have also identified a correlation between nadir CD4+ and risk of CH (25, 29); however, they included fewer people with a nadir CD4+ of less than 200, compared with our cohort where over 75% of individuals had a history of advanced HIV and the median nadir CD4+ T cell count was 33 cells/μL. The gene discussed is CD4; the disease is cyclic hematopoiesis.