CEACAM5 and interstitial lung disease: Due to heterogeneity, serum CA15-3 and CEA levels in other types of CTD-ILD were believed to be involved in the occurrence of Sjögren’s syndrome-associated ILD (7), Sargin G et al. (27) found that levels of serum CA125, CA153 and CA199 in patients with RA-ILD were significantly higher than those in RA patients without ILD; they proposed TMs as predictive biomarkers for RA-ILD.