EGFR and glioblastoma: The other three members of the EGFR RTK class appeared upregulated differentially in the various glioblastoma subgroups, with ERBB2 mild overexpression in the EGFR subgroup, especially associated with EGFRm cases, ERBB3 mild overexpression in PDGFRA and Other subgroups, and ERBB4, in the IDH subgroup.