ESM1 and neoplasm: Endothelial cell-specific molecule 1 (ESM1) is a dermatan sulfate proteoglycan secreted by endothelial cells that are regulated by possible markers of angiogenesis, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF).61–63 ESM1 is a biomarker associated with tumour progression in various types of tumours, including lung, liver, brain, kidney and gastric tumours.