From another perspective, Chi3L1 deficiency also obviously reduced the extent of fibrosis and hydroxyproline content in the lungs of BLM‐SSC mice (Figure S8A,B, Supporting Information).[33] ELISA and qPCR analyses revealed a decline in Col1A1 expression in the lungs of BLM‐SSc KO mice compared with BLM‐SSc WT mice, suggesting lung fibrosis mitigation (Figure S8C,D, Supporting Information). This evidence concerns the gene CHI3L1 and pulmonary fibrosis.