SMAD4 and neoplasm: In contrast, in either DTLL or the combination treatment group of SMAD4-deficient AsPC-1 models (shown in Fig. 5c), significantly increased expression of SMAD2/SMAD3 and SMAD4, as well as decreased SMAD7 were tested when compared to the control or gemcitabine, suggesting that DTLL combined with gemcitabine could obviously reactivate SMAD4, and thereby inhibit AsPC-1 tumor growth in a SMAD-dependent manner.