NOTCH4 and neoplasm: Notch1 and Notch4 are expressed in normal and tumor lymphatic endothelial cells, and Notch1 is activated in lymphatic endothelium of invasive mammary micropapillary carcinomas [39] These data suggest a role for cross-talk between VEGFR-3 and Notch in both tumor angiogenesis and lymphangiogenesis.