MYB and diffuse astrocytoma: Diffuse low-grade pediatric gliomas include four tumor types, three of which are new entities: diffuse astrocytoma with alterations in MYB or MYBL1, angiocentric glioma (most often associated with MYB-QKI fusion), polymorphous low-grade neuroepithelial tumor of the young (PLNTY) (19), and low-grade diffuse gliomas with alterations in the MAP kinase pathway (mainly FGFR or BRAF) (12).