CD4 and AIDS: Interestingly, the analysis of the data of our and other cohorts have shown that, in contrast with recent data from the Antiretroviral Therapy Cohort Collaboration (ART-CC) [15], a low CD4/CD8 ratio is a predictor of non-AIDS-related events independently from CD4 cell count [16, 17], while other studies have shown an association of this marker with non-AIDS-defining cancers [18] or, more recently, with pulmonary emphysema [19].