TGFB1 and exocrine pancreatic carcinoma: Hence, the decreased expression of E-cadherin by pancreatic carcinoma cells in vivo could reduce or abolish the ability of tumour antigen-specific T-lymphocytes in the TGFβ-rich cancer microenvironment to adhere to and lyse their targets, allowing cancer cells to escape from normal intraepithelial immunological surveillance.