CTSE and idiopathic pulmonary fibrosis: For example, up-regulated expression of candidate genes including CTHRC1, CTSE, GREM1, NELL1 and PLA2G2A in the core set, and AREG, FST, LOX, THBS1 and SELE in the advanced set, were also found to be increased in IPF animal models or in human IPF patients [7, 23–27].