WT1 fibroblasts expressed high levels of CTHRC1, POSTN, RUNX1, and several collagen genes, including COL1A1, COL1A2, COL3A1, COL4A5, COL6A3, COL14A1, and COL16A1 in patients with IPF compared with control individuals (Figure 2E). Here, COL6A3 is linked to idiopathic pulmonary fibrosis.