In line with a broad role for TH17 cells in autoimmunity, and consistent with the ability of the RhoA-ROCK pathway to regulate this TH subset, aberrant activation of this pathway has been observed in murine models of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and multiple sclerosis (MS). The gene discussed is RHOA; the disease is rheumatoid arthritis.