PDGFRA and astrocytoma (excluding glioblastoma): Furthermore, CDKN2A was completely inactivated in all the grade 4 IDHmut astrocytomas with PDGFRA amplification in TCGA and GLASS data with an exception of two cases (one in the GLASS and one in TCGA dataset), which carried only a PDGFRA amplification (Additional file 2: Fig. S2f and S3c).