In posterior fossa A (PFA) ependymomas, one subtype of ependymomas (EPN) is rarely mutated for H3.3K27M but these tumours have increased expressions of the enhancer of zeste homologue inhibitory protein (EZHIP), which causes reduced H3K27 methylation like in H3K27M, suggesting the importance of H3K27 residues as hotspot mutations in brain tumorigenesis (Jenseit et al., 2022; Hubner et al., 2019; Ryall et al., 2017). The gene discussed is EZHIP; the disease is ependymoma.