PDGFRA and ependymoma: Spinal ependymomas comprise: 1) myxopapillary ependymomas, grade 2 tumors involving the cauda equina/filum terminale and showing overexpression of HOX, NEFL, and PDGFRA genes; 2) spinal ependymomas, grade 3 lesions characterized by NF2 (Merlin gene) alterations that can be targeted by MEK inhibitors and VEGF inhibitors; 3) spinal ependymomas with MYCN amplification, grade 3 entities with worse prognoses and higher propensity of leptomeningeal spread, but with no available clinical trials on MYCN-targeting inhibitors (80).