DLL4 and neoplasm: We have shown that in ECs, VEGFA upregulates FABP4 expression indirectly by inducing DLL4, which activates NOTCH1 signalling and initiates FABP4 gene transcription.17 However, tumour angiogenesis in FABP4−/− mice, and its relation to NOTCH1/ VEGFA signalling pathways and endothelial FA metabolism, has not been studied in detail.11 In this study, we aimed to investigate the role of FABP4 in ovarian tumour angiogenesis and in EC FA metabolism.