CDKN2A and ganglioglioma: Three gangliogliomas with BRAF p.V600E mutation had concurrent CDKN2A homozygous deletion (SF-GG-3, SF-GG-9, and SF-GG-11) and one of these three tumors additionally harbored a subclonal missense mutation in the PTEN tumor suppressor gene (SF-GG-3).