PTPN2 participates in multiple pathological processes, including inflammatory reaction, tumorigenesis, and immune regulation.[5] Multiple studies demonstrated PTPN2 as a tumor suppressor in human T‐cell acute lymphoblastic leukemia (T‐ALL).[23] PTPN2 inactivation was reported in 2 out of 39 (5%) cases of peripheral T‐cell lymphoma not otherwise specified (PTCL, NOS).[24] In contrast, Prutsch N et al. Here, PTPN2 is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.