To explore the influence and molecular mechanism of leucine‐rich repeat containing 15 (LRRC15) in rheumatoid arthritis (RA) model induced by collagen‐induced arthritis (CIA) in rats and interleukin‐1 beta (IL‐1β) treated fibroblast‐like synoviocytes (FLSs). Here, LRRC15 is linked to rheumatoid arthritis.