We believe that the IL-17F+ IL-10- T17 cell subset is also pathogenic, at least in some patients, as dual inhibition of IL-17A and IL-17F produces higher PASI (Psoriasis Area and Severity Index) 100 responses (complete skin clearance) compared to results obtained with antibodies that neutralize IL-17A only (33). The gene discussed is IL17A; the disease is psoriasis.