The ST-EPN-RELA subgroup can be identified by immunostaining for the surrogate markers L1 cell adhesion molecule (L1CAM) or anti-NFkB (p65, RelA) [15], the latter based on the discovery that C11orf95–RELA fusions drive oncogenic NF-kB signalling in ependymoma [33]. Here, L1CAM is linked to ependymoma.