Recombinant signal binding protein for immunoglobulin kappa-J region (RBPJ), the nuclear binding partner of activated NOTCH1’s intracellular binding domain (NICD), was mutated (n = 5) or homodeleted (n = 1) in 3% (6 of 169) of oligodendrogliomas. This evidence concerns the gene RBPJ and oligodendroglioma.