CD4 and AIDS: We now also know that early treatment of HIV leads to a substantial reduction in the occurrence of both acquired immune deficiency syndrome (AIDS)-defining conditions and serious non-AIDS events [7], but there nonetheless remains clinical interest in understanding the factors that are predictive of the recovery in CD4 counts upon HAART initiation as for many patients there is a substantial delay between infection and diagnosis and suboptimal CD4 recovery remains a concern for patients and clinicians [13].