The limited efficacy of anti-IL-17A monoclonal antibodies in RA clinical trials (e.g., secukinumab 99, brodalumab 100, CNTO6785 101) further underscores human-mouse differences, and suggests that IL-17-associated pathways, while prominent in murine arthritis, may play a subordinate role in human RA. The gene discussed is IL17A; the disease is rheumatoid arthritis.