MAP2K7 and brain neoplasm: Owing to these widespread effects, we cannot rule out the influence of H3 mutations on the efficacy of concurrent PI3K and MEK inhibition.42 PI3K signaling has been shown to be aberrantly activated in many pediatric CNS neoplasms irrespective of H3K27 mutation status and agents targeting PI3K signaling are in clinical trials for pediatric brain tumors of various etiologies.43