IDH1 mutations are present in both precursors of AML and glioblastoma, i.e., myelodysplastic syndromes (MDS) (5%) and diffuse anaplastic astrocytoma (>80%), with different impacts on their malignant transformation rate; this mutation accounts for malignant transformation in 50% of cases of MDS, while it is not associated with the rate nor the time to malignant transformation of low-grade gliomas [43]. Here, IDH1 is linked to myelodysplastic syndrome.