KDR and neoplasm: We also included Fgfr1f/f; Fgfr2f/f (double floxed, DFF, used as control) and Vegfr2+/+; Fgfr1f/f; Fgfr2f/f (double conditional knockout, DCKO) mice in the study, to determine the extent of crosstalk between VEGF and FGF signaling in tumor angiogenesis.