TGFB1 and cancer: Like in embryonic development, metastasis in cancer progression can also be induced by various signaling molecules or cytokines [27], such as proteins in the TGF-β superfamily [28], hedgehog (HH) family, WNT family [29], and interleukin (IL) family [30], etc. Stressful microenvironments, such as hypoxia [31] or free radicals [32], also trigger EMT [33].