XDH and colorectal carcinoma: The high-risk genes (GPX3, AKR1C4, SPHK1, ADCY5) were more likely to be expressed in the high-risk group patients, while low-risk genes (NAT2 and XDH) were expressed in the low-risk group patients of TCGA-CRC (Fig. 3A) and GEO-CRC (Fig. 3B).