KIAA1549 and pilocytic astrocytoma: Recent studies have shown that pilocytic astrocytomas near universally harbor abnormalities in the MAPK pathway, and most commonly a tandem duplication targeting chromosome 7q, which gives rise to a KIAA1549–BRAF fusion gene consisting of the N terminus of KIAA1549 and the kinase domain of v-RAF murine sarcoma viral oncogene homolog B1 (BRAF) [44].