TGFB1 and malignant colon neoplasm: TGF-β signaling was significantly increased in HCT116 human colon cancer cells treated with doxorubicin, and inhibition of TGF-β signaling markedly increased the sensitivity of HCT116 cells to doxorubicin [24], suggesting the role of elevated TGF-β signaling in resistance to doxorubicin.