HIF1A and colorectal cancer: Overexpression of prolidase in colorectal cancer cells contributed to increase in nuclear hypoxia-inducible factor (HIF-1α) level and HIF-1α-dependent gene products, e.g., vascular endothelial growth factor (VEGF) and glucose transporter-1 (Glut-1) (Surazynski et al. 2008a).