Interestingly, potentially activating mutations in the intracellular domain of NOTCH2 were additionally found in two other PTCL, NOS described above, (LYWS-1313 LYWS-1061) both of which showed Th1-differentiation/PTCL-TBX21 by the immunohistochemical algorithm [65]. This evidence concerns the gene TBX21 and mature T-cell and NK-cell non-Hodgkin lymphoma.