YAP1 and supratentorial ependymoma: YAP and TAZ fusion proteins would soon be found to define subtypes of supratentorial ependymoma (Pajtler et al. 2015, Parker et al. 2014), poroma and porocarcinoma (Sekine et al. 2019), and an increasing number of solid tumors (Garcia et al. 2022, Szulzewsky et al. 2021).