PTK7 and glioblastoma: The G6/Multi-RTK subgroup assembles tumors showing RTK genomic heterogeneity, but a multitude of RTKs without genomic alterations are overexpressed in glioblastoma, such as KDR, MET, NTRK1, ALK, ERBB2, EPHB1-4, EPHA3, PTK7 and ROR1-2, with or without preferential expression in the G1-G7 molecular subgroups [4].