TGFB1 and pancreatic ductal adenocarcinoma: Both, Nrf2 [17,21,30] and TGF-β1 [2,31,32] have been shown to be involved in the development of pancreatic ductal adenocarcinoma (PDAC) and to confer malignant properties already to untransformed pancreatic ductal epithelial cells [33–35].