PRDM1 and mature T-cell and NK-cell non-Hodgkin lymphoma: This recurrent abnormality, which is observed in 29-52% of ENKTCL arising in immunocompetent individuals, encompasses loci of the FOXO3 and PRDM1 genes, which have been shown to function as tumor suppressors in ENKTCL and subtypes of PTCL.