When the CD4+ cell count was less than 450 cells/mm3, psoriasis patients infected with 80% HIV were in the progressive stage; when the CD4+ cell count was less than 200 cells/mm3, the risk of psoriasis exacerbation was nine times higher (Alpalhão et al., 2019); both these conditions were associated with TNF-α and IFN-γ (Craven et al., 2001). Here, CD4 is linked to psoriasis.