CD4 and AIDS: A recent study demonstrated that deferred initiation of ART at CD4 levels 251 to 350 cells/μL was associated with higher rates of AIDS and mortality, compared to starting ART at the range of 351 to 450 cells/μL (HR: 1.28, 95% CI: 1.04–1.57), and that the adverse effect of deferring treatment increased with the decreasing CD4 cell count threshold [29].