In the present study the 13 IRGs that were strongly associated with CRC prognosis—CXCL1, F2RL1, LTB4R, GPR44, ANGPTL5, BMP5, RETNLB, MC1R, PPARGC1A, PRKDC, CEBPB, SYP, and GAB1—were used in the classifier investigation. This evidence concerns the gene PTGDR2 and colorectal carcinoma.