NFKB1 and mature T-cell and NK-cell non-Hodgkin lymphoma: Different GEP studies have suggested that PTCL/NOS may show up- or downregulation of NF-κB molecules,14, 15, 98 with possible prognostic implications (see above).14, 98 However, these studies included a limited number of PTCL/NOS14 or cases with prominent non-neoplastic components.15 By contrast, we found that PTCL/NOS mostly consisting of neoplastic cells present with global downregulation of NF-κB genes in comparison with normal T lymphocytes.