IDH2 and mature T-cell and NK-cell non-Hodgkin lymphoma: Compare to PTCL-NOS, AITL is characterized by high frequencies of overlapping mutations in epigenetic modifiers in neoplastic T cells, including TET2 (80%), RHOA (70%), DNMT3A (33%), IDH2 (20-40%), and CD28 genes (35–37).