SMAD4 loss contributes to chemoresistance of PDAC cells. AsPC-1, CFPAC-1 and PANC-1, SMAD4 deficient and proficient cells were treated with different concentration of cisplatin (Cis; 5 μM), paciltaxol (Pac; 1 μM) and gemcitabine, (Gem; 2 μM) for 3 days. Chemosensitivity testing of PDAC cells using the MTT colorimetric assay. The data indicates SMAD4 increases drug sensitivity to three different chemo drugs in PDAC cells. Data were means ± SD of triplicates. *P < 0.01.