CD4 and AIDS: Today, people living with HIV (PLWH) timely diagnosed and starting treatment with CD4 counts ≥350 cells/μL have life expectancies close to the general population.1, 2, 3, 4, 5, 6, 7, 8 Still, despite the enormous advances achieved in the field, approximately half of PLWH in Western countries are diagnosed at a late disease stage, defined as CD4 cell count below 350 cells/μL or presentation with an AIDS-defining event, regardless of the CD4 cell count.9