TGFB1 and neoplasm: In ovarian cancer, tumor cell-derived exosomes carrying CMTM4 are taken up by macrophages, promoting TGF-β1 and CXCL12 secretion via NF-κB pathway activation and enhancing ICAM1/CD206-mediated M2 polarization, thereby reducing the efficacy of PD-1 inhibitors (203).