HLA-A and embryonal neoplasm: High-grade gliomas (e.g., H3K27M-DMG, H3G34-DHG) exhibited elevated HLA class I (HLA-A, HLA-B, and HLA-C) expression, facilitating stronger immune recognition, while embryonal tumors (e.g., medulloblastoma, MRT) displayed significantly lower levels, suggesting an immune-cold phenotype with reduced antigen presentation potential.