It has been verified in anti‐type II collagen antibody‐induced arthritis model that LECT2‐deficient mice suffered from aggravated arthritis, which was evidenced by serious swollen hind paws, incremental cartilage erosion and increased inflammatory cytokines such as IL‐1β and IL‐6, compared with the wild‐type controls. The gene discussed is IL1B; the disease is arthritic joint disease.