YAP1 and posterior fossa ependymoma: Anatomically, ependymoma is classified into spinal, infratentorial, and supratentorial subgroups, while molecularly, they are classified as follows: supratentorial ependymoma with ZFTA fusion (ST-EPN-ZFTA), supratentorial ependymoma with YAP1 fusion (ST-EPN-YAP), supratentorial ependymoma without ZFTA or YAP1 fusion, posterior fossa ependymoma group A (PF-EPN-A), and posterior fossa ependymoma group B (PF-EPN-B) (11).