The primary diseases included germinomas (n = 2), acute lymphoblastic leukemias (n = 2), medulloblastomas (n = 3), diffuse astrocytoma with IDH2 mutant (n = 1), pilocytic astrocytoma (n = 1), pituitary adenoma (n = 1), and a metastatic brain tumor from lung cancer (n = 1). Here, IDH2 is linked to diffuse astrocytoma.