IDH1 and glioma: For example, while IDH1/2 mutations are known to be associated with young adult gliomas (Haase et al., 2018; Yan et al., 2009), our paired mutation-subtype analysis provides improved resolution, showing IDHmut-non-codel glioma enrichment in young adults whereas IDHmut-codel gliomas are enriched in later-onset cases (Figure 1B).