PPM1D and brain stem glioma: Subsequent studies have confirmed PPM1D mutation frequencies of up to 9%–25% in DIPG.[6, 8, 9, 10] PPM1D mutation is also related to the chemotherapy resistance of myeloid cancer.[11] We found that during clinical treatment, patients with brainstem glioma with PPM1D mutation have a shorter median survival time than PPM1D wild type patients.