PLP1 and glioblastoma: These include sox10, foxd3, sox2, plp1, the mammalian orthologues of which are expressed by mouse EGCs, tfap2a, a gene required for early NC development, col28a1b, whose mammalian orthologue is a peripheral glial marker, as well as ptprz1a, and ptprz1b, which have been identified in glioblastoma stem cells.