Endothelial FABP4 expression in normal and tumour tissues of ovary and brain has been reported.11, 26 It has been shown previously only that adipocyte FABP4 expression is important for promoting ovarian carcinoma.10 We observed that endothelial FABP4 expression in vivo was enhanced in DLL4-overexpressing tumour xenografts, demonstrating the in vivo induction of FABP4 directly by NOTCH1 signalling. This evidence concerns the gene DLL4 and neoplasm.