ZIC1 and medulloblastoma: While ZIC4 is coregulated with ZIC1 through recurrent epigenetic suppression and copy number changes, the functional role of ZIC4 in G3 medulloblastoma cell lines is minimal compared to that of ZIC1. Furthermore, somatic point mutations have only been identified for ZIC1 and not for ZIC4. As such, we predict that ZIC1 has a more dominant role in medulloblastoma tumorigenesis, with ZIC4 potentially providing some additive effects.