FBXW7 and neoplasm: Furthermore, 50% reduction of DEspR expression in heterozygous DEspR+/− knockout mice is not embryonic lethal [28] in contrast to the embryonic-lethal phenotype of heterozygous VEGF+/− knockout mice [23], [24], and decreased tumor growth in DEspR+/- male mice [22], in polar contrast to increased tumorigenesis expected from the loss of Fbxw7-tumor suppressor functions as seen in human cancer and mouse tumor inactivating mutations [27], [29].