CTHRC1 and pulmonary fibrosis: In addition, we focused on the two molecular targets among previously reported 12 IPF lung-relevant translational gene markers, namely, collagen triple helix repeat containing protein 1 (CTHRC1) and four-and-a-half LIM domain protein 2 (FHL2); the levels of these two proteins were stimulated in the bleomycin-induced lung fibrosis model and attenuated by pirfenidone.