TGFB1 and Peritoneal Fibrosis: Mesothelial cells have been reported to play an important role in the development of peritoneal fibrosis caused by high glucose exposure, mainly through the TGF‐β/Smad signaling pathway, but not by equimolar concentrations of d‐mannitol (Devuyst et al., 2010; Ito et al., 2024; Jiang et al., 2020; Kang et al., 1999).