IL17A and psoriasis: Despite their efficacy in psoriasis however, brodalumab and secukinumab did not show efficacy (or were even detrimental) in other Th17-related diseases like RA or Crohn's disease [reviewed in Yang et al. (81)], suggesting that Th17 may use mechanisms othr than IL-17 to drive inflammation in different organs and tissues, and/or that targeting the Th17 lineage rather than IL-17 alone could provide better clinical efficacy.