In mouse models of anti‐type II collagen antibody‐induced arthritis, it was observed that the use of melatonin contributed to increased infiltration of inflammatory cells, exacerbation of synovial hyperplasia, and worsened articular cartilage destruction while markedly decreased expression of Cry1, suggesting that protein Cry1 might be involved in the melatonin‐mediated aggravation of joint inflammation and destruction [55]. Here, CRY1 is linked to Arthritis.