Endothelial cell-specific molecule 1 （ESM1） is a proteoglycan secreted by endothelial cells （mostly in the human lung and kidney tissues） and its mRNA expression is regulated by inflammatory cytokines. ESM1 has potent implications in lung endothelial cell-leukocyte interactions. In addition， ESM1 expression is detected in various epithelia and in adipocytes. ESM1 is involved in angiogenesis and it also promotes angiogenic sprouting. ESM1 expression is upregulated by TNF alpha， IL1 beta， or lipopolysaccharide and downregulated by IFN gamma. Genetically engineered cells overexpressing ESM1 induce tumor formation， implying that ESM1 might be involved in the pathophysiology of tumor growth in vivo.
