Moreover, in the synovial tissue of rheumatoid arthritis patients, DDR2 mRNA expression was significantly associated with the levels of pro-inflammatory IL-15, and collagen-induced activation of DDR2 in human fibroblast like synoviocytes results in increased IL-15 production thus promoting inflammation (Mu et al., 2020). The gene discussed is IL15; the disease is rheumatoid arthritis.