These cells were composed of hyperchromatic cells forming a rosette-like structure and were immunopositive for GFAP with reduced expression of H3K27me3, which is consistent with the occurrence of a metastatic EPN-PFA (WHO CNS grade 3, based on 5th ed WHO Classification of CNS Tumor, 2021) (Figure 3F,G,H). Here, GFAP is linked to central nervous system neoplasm.