Patient mutation data from online databases cBioPortal (https://www.cbioportal.org/) and COSMIC (https://cancer.sanger.ac.uk/cosmic3d/) were reviewed to determine the most common SMARCA4 genetic alterations specific to MB, ATRT, oligodendroglioma (low-grade glioma) and GBM (high-grade glioma). The gene discussed is SMARCA4; the disease is oligodendroglioma.