Our G3/G4 expression continuum—of which KIRREL2 expression is a key constituent—was also projected onto an scRNA‐seq expression atlas of early human foetal cerebellar development [10], showing that the continuum is mirrored by a specific developmental trajectory—beginning with early rhombic lip (RL) precursors (most MBGrp3‐like) and ending with differentiated unipolar brush cells (UBCs) (most MBGrp4‐like)—linking individual tumours to specific developmental states by their position on the continuum. Here, KIRREL2 is linked to neoplasm.