Recent large-scale genomic profiling studies of glioma have yielded a proliferation of candidate subclasses, biomarkers and therapeutic targets for investigation. Some findings, such as that of IDH mutation in low-grade gliomas and secondary glioblastoma (GBM), fit well into established notions of different routes of gliomagenesis. Other results, such as the division of primary GBM based on signaling pathway alterations, suggest new pathogenetic routes with implications for treatment. The analysis of this data is still in the early stage. Nonetheless, several preliminary findings merit consideration in the development and interpretation of current clinical trials.