IGF1 and intestinal neoplasm: Second, insulin promotes colon cancer progression by increasing the expression of acyl-coenzyme A: cholesterol acyltransferase-1 (33), increasing the expression of vascular cell adhesion molecule-1 in intestinal tumor endothelial cells and causing a proinflammatory state (34), and elevating the levels of IGF-1, which promotes cell proliferation, survival, and angiogenesis by stimulating the synthesis of vascular endothelial growth factor (35).