Regarding HIV-related variables and ART, people with CF had longer time since HIV diagnosis (CF: 30 years vs. F+/ICT−: 30, F−/ICT+: 26, F−/ICT−: 26; P < 0.001), lower CD4+ nadir (CF: 154 c/μl vs. F+/ICT−: 176, F−/ICT+: 200, F−/ICT−: 204; P < 0.001), lower % current CD4+ cell count (CF: 32% vs. F+/ICT−: 33, F−/ICT+: 36, F−/ICT−: 36; P = 0.007) and lower CD4/CD8 ratio (CF: 0.87 vs. F+/ICT−: 0.90, F−/ICT+: 1.03, F−/ICT−: 0.96; P = 0.016), when compared to other groups. The gene discussed is CD4; the disease is cystic fibrosis.