TGFB1 and Peritoneal Fibrosis: Peritoneal fibrosis is characterized by fibroproliferative changes in the peritoneal membrane, the denudation and altered appearance of peritoneal mesothelial cells (PMCs), accumulation of extracellular matrix (ECM) molecules in submesothelial areas and vasculopathy.7, 8, 9 The key mediator of this process is transforming growth factor (TGF)‐β.