NF1 and neurofibroma: The regulation of Cdkn2a gene by PRC2 has relevance to the Schwann cell–derived tumors in neurofibromatosis caused by mutation of the NF1 tumor suppressor gene (50), The progression from neurofibromas in NF1 to the more malignant form called malignant peripheral nerve sheath tumor is often accompanied by comutation of the CDKN2A gene and genes encoding subunits of the PRC2 complex (e.g., EED and SUZ12) (27, 28, 29).