Data evaluation showed that the panel is very well suited for diagnostics of T-cell lymphomas with TFH phenotype (AITL and nodal PTCL with TFH-phenotype, currently under the common umbrella of TFH-cell lymphomas both in the 5th edition of the WHO classification and in the ICC) (1, 2), with 48/53 (91%) cases showing at least one mutation, most frequently of TET2 (45/53, 85%), RHOA (23/53, 47%), DNMT3A (19/53, 36%) and IDH2 (8/53, 15%) (Figure 1D). The gene discussed is IDH2; the disease is mature T-cell and NK-cell non-Hodgkin lymphoma.