On the other hand, HIV infection is characterized by a progressive decrease in CD4+ T-cell count, and it could seem paradoxical that psoriasis exacerbations are more frequent in this subset of patients than the general population [60]; however, when psoriasis is associated with HIV infection, it is more severe due to the low control of the immune response: it was shown that with a CD4+ T-cell count <200/μL, there is a risk 9-fold greater of a severe form [61]. The gene discussed is CD4; the disease is HIV infectious disease.