Considering the biological activities of CHI3L1 determined in RA and hepatic fibrosis such as stimulating the growth of fibroblasts (19), driving macrophage activation and differentiation (53), and regulating the ECM (54), it may have a significant impact on the potential pathobiology of both IPF and RA-ILD. The gene discussed is CHI3L1; the disease is Hepatic fibrosis.