,33 Although the utility of combined p16 and MTAP IHC as a substitute for CDKN2A molecular testing has been previously reported in several cancers, including esophageal noninvasive precursor lesions, pancreatic neoplasia, lung cancer, pleural mesothelioma, and diffuse and circumscribed gliomas,24,25,34–36 to the best of our knowledge this has not been explored in PXA. The gene discussed is MTAP; the disease is central nervous system cancer.