another interesting result from the African Temprano Trial, presented at the conference on Retroviruses and Opportunistic Infection (CROI 2015), showed that starting HIV/AIDS treatment (TDF was one of the drugs they used) at a CD4 cell count above 500 reduced the risk of serious illness and death by 44 % when compared to starting treatment according to WHO guidelines [31]. This evidence concerns the gene CD4 and Opportunistic infection.