IDH1 and neoplasm: A methylation result—especially a low-confidence or borderline one—must be interpreted in light of the tumor’s morphology, IHC profile (e.g., IDH1 R132H, H3K27me3, SMARCB1), and molecular findings (e.g., IDH mutation, 1p/19q codeletion, ZFTA/YAP1 fusion).