IL17A and psoriasis: To further dissect the role of different sources of IL-17A in psoriasis, this study investigated serial biopsies taken from active plaques at Baseline and treatment Weeks 2 and 12 during a phase 2 trial in which subjects with moderate-to-severe psoriasis received 1 of 3 induction regimens with the IL-17A-selective antibody secukinumab.