GPX4 and colorectal carcinoma: Moreover, rs5859 (SEP15) induces a base change in the SECIS element of SEP15 mRNA resulting in an alteration Sec insertion, via a mechanism comparable to rs713041 in GPX4. Sep15 like SelS is involved in in the control of protein folding in the ER and genetic interactions were identified between rs7579 and rs3877899 in the SEPP1 gene and rs5859 in relation to CRC risk [78].