KIAA1549 and pilocytic astrocytoma: The high level of phospho-ERK expression in chordoid gliomas was equivalent to that seen in other glioma types harboring known genetic alterations within the MAP kinase signaling pathway, including pleomorphic xanthoastrocytoma with BRAF V600E mutation and pilocytic astrocytoma with KIAA1549-BRAF gene fusion (Fig. 3).