GPX6 and rectal cancer: Selenoprotein genes nominally associated with CRC risk included several with limited or no prior evidence (DIO1, GPX6, SELENOM, SELENON, SELENOT, SELENOV) and those reported in several studies (GPX1, GPX4, SELENOF, TXNRD1, TXNRD2, TXNRD3) for an association with CRC (or specifically colon or rectal cancer) risk.