IL17A and arthritic joint disease: Results of other recent studies have called into question the idea that IL‐22 has a solely pathogenic role in arthritis, as antigen (methylated bovine serum albumin [BSA])–induced, IL‐17–mediated joint inflammation was found to occur independent of IL‐22 (43) and systemic administration of rIL‐22 was protective in late stages of disease in the CIA model (44).