PRKCA and glioblastoma: For detection of the PRKCA D463H mutation, which is characteristic for chordoid gliomas [10, 11], we designed a dual probe ddPCR assay (Additional file 1: Table S1) and investigated FFPE DNA extracted from three tumors histologically classified as chordoid glioma and from five glioblastoma samples (Table 1, Additional file 1: Fig. S5).