CDKN2A and schwannoma: Germline mutation/deletion of the CDKN2A gene on chromosome 9p21.3 (which encodes a negative regulator of the cell cycle p16INK4a) or the DGCR8 gene on chromosome 22q11.21 (which encodes a subunit of the microRNA processing complex) causes rare tumor predisposition syndromes that may be associated with development of multiple schwannoma or schwannoma-like nerve sheath tumors [1, 12, 13].