In the non‐AITL (mainly PTCL‐NOS) groups, the genes with comparably high mutation rates were TET2 (33%), TP53 (18%), RHOA (15%), FAS (12%), KRAS (12%), MTOR (12%), STAT3 (12%), KMT2D (9%), DNMT3A (9%), IDH2 (9%), ARID1A (6%), ATM (6%), FAT1 (6%), MED12 (6%), and STAT5B (6%). The gene discussed is ARID1A; the disease is mature T-cell and NK-cell non-Hodgkin lymphoma.