Abnormal activation of EZHIP in Posterior fossa type A (PFA) ependymomas, some osteosarcomas, diffuse midline gliomas, and rare non-CNS tumors, is strongly implicated in oncogenesis due to global loss of the repressive histone mark H3K27me3 and epigenetic deregulation of PRC2 targets even in the absence of the H3K27M oncohistone mutation (Cassim et al., 2024; Hübner et al., 2019; Jawhar et al., 2025; Jenseit et al., 2022). The gene discussed is EZHIP; the disease is ependymoma.