An intracrine VEGF-A/VEGFR-1 signaling was found to mediate the survival of colorectal cancer cells, as indicated by the decrease of cell survival (reduced proliferation/increased apoptosis) and the increase of sensitivity to chemotherapy shown by the human colorectal cancer HCT116, SW480, and HT29 cell lines, after VEGF-A or VEGFR-1 silencing through RNA interference [218]. The gene discussed is FLT1; the disease is colorectal cancer.