The glaring discrepancy between the aggressiveness of PTCL-EBV tumors and its low genomic instability was proposed to be due to suppression of instability by underlying NF-κB activation amidst a paucity of TP53 mutations, which might contribute towards the low genomic instability but high aggressiveness of this tumor. This evidence concerns the gene NFKB1 and mature T-cell and NK-cell non-Hodgkin lymphoma.