MTAP and meningioma: As previously reported [21, 28], p16 IHC is a reliable screening tool for identifying cases that should undergo molecular analysis for CDKN2A. In the context of a higher-grade meningioma (e.g., elevated mitotic count, brain invasion, or other concerning features such as pattern loss, significantly increased proliferative activity, or necrosis) and p16/MTAP negativity, testing for a possible CDKN2A deletion is the next step.