IDH1 and angioimmunoblastic T-cell lymphoma: IDH1/2 mutations are also present in hematological malignancies, mainly in acute myeloid leukemia (AML, ~ 20%) [5, 12], but also in myeloproliferative neoplasms (MPN, ~ 1–4%) [13], in myelodysplastic syndromes (MDS, ~ 5%) [12] and angioimmunoblastic T‐cell lymphomas (AITL, ~ 20–30%) [5, 14].