COL3A1 and pulmonary fibrosis: It was found that only IPF was characterized by similar expression profile with asthma- and bleomycin-driven lung fibrosis in mice: a range of known fibrosis-related markers, including COL1A1, COL3A1, IGF1, CXCL12, SPP1, and MUC5B, were found to be upregulated in lung tissue but not in peripheral blood of IPF patients (Figure 9).