PRDM6 overexpression secondary to a tandem duplication of the SNCAIP locus is a suspected G4 medulloblastoma driver gene14, and in our dataset it is found only in G4 tumors with mono-allelic expression of ZIC1 or ZIC4 (Fig. 4a and Extended Data Fig. 4a). This evidence concerns the gene ZIC1 and medulloblastoma.