CAT and pulmonary fibrosis: We found that circulating CRP levels positively correlated with CRP, IBP2, CHI3L1, FGB, FHR5, IGHV3-73, FGG, PRSS2, CFP, CFH, CD163, FCGBP, and CAT exosomal proteins, which are linked to inflammation, complement activation, and pulmonary fibrosis (Lu et al., 2011).