Mutations in genes encoding subunits of the SWI/SNF complex are also present in other tumours, including gliomas, medulloblastomas, and squamous cell carcinomas,3, 58, 59 where mutations in SWI/SNF complex subunit genes include mutations in BRG1 and, to a lesser extent hBRM.58 Here, SMARCA1 is linked to medulloblastoma.