P4HA1 and colorectal cancer: Gene expression data from 433 human colorectal cancer specimens in the TCGA database were used to compare levels of GLS1 mRNA with a HIF metagene signature based on the expression of VEGFA, PDGFB, LOX, CXCR3, ANGPTL4, L1CAM, SLC2A1, P4HA1, P4HA2, and MET mRNA, which are all HIF-regulated genes.