SRF and idiopathic pulmonary fibrosis: Clinically, fibroblasts from IPF patients are hypermethylated at the CDKN2B gene locus, which functions as a cyclin dependent kinase inhibitor, and therefore its reduced expression resulted in myofibroblast differentiation via SRF (serum response factor) and MRTF-A (myocardin-related transcription factor A) but not by cell proliferation (Scruggs et al., 2018).