CTHRC1 and idiopathic pulmonary fibrosis: Furthermore, pathological fibroblasts (pFBs) expressing markers such as CTHRC1 and SPARC were found to be enriched in PC-19-PF and IPF patients, indicating a common fibrotic process and supporting the possibility of repurposing antifibrotic therapies approved for IPF in the treatment of PC19-PF [76].