Until now, a few studies have estimated the duration from HIV infection to its diagnosis, most of which were qualitatively carried out with varying definitions of delayed diagnosis; i.e., time-based definition (less than a year from diagnosis to the development of AIDS), CD4 count at the time of diagnosis (ranged 50–350 μl), or clinically symptomatic at the time of diagnosis (10). This evidence concerns the gene CD4 and AIDS.