Specifically, to classify the six types according to the 2021 WHO rule, the model needs to identify discriminative morphology related to histologic types (A, O, and GBM) and grades within types (A2/3/4, O2/3), and tumor genotypes with shared histologic features (e.g., IDH-wildtype and -mutant tumors). This evidence concerns the gene IDH1 and neoplasm.