FLT4 and anemia (phenotype): A) Global Vegfr3+/−: Embryos appear phenotypically normal (17). Lymphedema due to hypoplastic cutaneous lymphatic vessels (18) B) Global Vegfr3−/−: Embryonic death beginning at E10.5, prior to lymphatic vessel emergence/sprouting. No live-born pups (17). Abnormal vasculature, enlarged vascular bed formation, severe anemia before embryonic death (19)