TGFB1 and neoplasm: The hypothesis of “seed and soil” has been widely accepted, which suggests that the interaction between cancer cells and the peritoneal microenvironment leads to PD.29 A completely confluent mesothelial layer is the first barrier against bacterial invasion and tumor attachment.30 Our previous results demonstrated that intraperitoneal exfoliated GC cells induced senescence and apoptosis in HPMCs, leading to exposure of the subcutaneous matrix and forming a favorable apterium for GC cell implantation.22, 31 This injury of HPMCs was mainly mediated by TGF‐β1.