It has been posited that TET2 mutations noted in nodal TFH lymphomas largely arise in the setting of clonal hematopoiesis, which is supported by the fact that TET2 mutations in T cell lymphoma patients are frequently found to co-occur in the non-neoplastic B lymphocyte, myeloid and HSC compartments as well as the neoplastic T cells (14, 49, 50). The gene discussed is TET2; the disease is lymphoma.