In the tumor tissues of the CRC patients from Ireland, compared to the matched controls, GPX2, GPX4, TXNRD3, and SOD2 were up-regulated (p = 0.023, 0.039, 0.003, and 0.036, respectively), while SELENOP, SELENOS, GPX3, SEPHS2, SELENBP1, and SELENOK were considerably down-regulated (p = 0.001, <0.001, <0.001, 0.002, <0.001, and 0.015, respectively). The gene discussed is GPX3; the disease is neoplasm.