{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"H3K27me3 is a downstream target of the polycomb repressive complex 2 (PRC2); PRC2 contains evolutionarily conserved proteins essential for regulating gene expression. Gain- or loss-of-function mutations in EZH2, a component of PRC2, have been found in a variety of cancer types such as Lymphoma, Melanoma, and Myelodysplastic Lymphoma; gain-of-function mutations can result in H3K27Me hyperactivity and chromatin dysregulation. KDMA6A and B demethylases can act on H3K27Me, and loss-of-function mutations in these proteins have been found in solid and non-solid tumors including types of Leukemia, Lymphoma, Melanoma, Renal and Bladder Cancers, Medulloblastoma and Prostate Cancer.\n As a gene transcription repressor, H3K27me3 has diverse roles in embryogenesis and neoplasia. Loss of H3K27me3 occurs in a significant subset of Malignant Peripheral Nerve Sheath tumors. Other neoplasms may show loss of H3K27me3 expression, such as Meningioma, Radiation Associated Unclassified Sarcoma, Radiation-Associated Angiosarcoma, Dedifferentiated Chondrosarcoma, Melanoma and Merkel Cell Carcinoma, amongst others. Some tumors may exhibit heterogeneous H3K27me3 expression (mosaic pattern)."}]}]}