Immunohistochemical evaluation of IDH2, DNAJA2 and citrate synthase showed diffuse cytoplasmatic staining of both neoplastic and non-neoplastic cells in the tumor microenvironment in both MPN-AITL and R-AITL samples (Figure 2A,D,G). This evidence concerns the gene IDH2 and angioimmunoblastic T-cell lymphoma.