The prognosis of PTCL-NOS relies on its genetic heterogeneity, leading to its classification based on gene expression profiles: one with high expression of GATA3 (PTCLGATA3) and the other with high expression of TBX21 (PTCL-tbx1) [39]. This evidence concerns the gene TBX21 and mature T-cell and NK-cell non-Hodgkin lymphoma.