SMAD4 and neoplasm: For SMAD4-sufficient MIA PaCa-2 tumor models, the ratios of p-EGFR/EGFR, p-HER-2/HER-2, p-AKT/AKT, and p-mTOR/mTOR as well as PD-L1 expression were more effectively inhibited after treatment with DTLL or both than in gemcitabine or control-treated groups, whereas slightly decreased SMAD4 and dramatically increased SMAD7 were observed.