In a previous study performed in patients with PsO we found that CXCR3+ and CCR5+ CD4+ Th1 cells in the circulation inversely correlated with Psoriasis Area and Severity Index and that the expression of CXCR3 and CCR5 mRNA was increased in psoriatic skin as compared to normal skin leading to the hypothesis of a specific recruitment of CXCR3+ cells to the inflamed psoriatic tissues16,17. Here, CD4 is linked to psoriasis.