CDKN2A and pleomorphic xanthoastrocytoma: Therefore, our study aimed to assess a cohort of patients with PXA and compare p16 and MTAP IHC with CDKN2A, CDKN2B, and MTAP deletion status by whole-genome copy number microarray-based analysis, and to determine if IHC is a reliable surrogate for assessing CDKN2A HD.