CTNNB1 and Mobius syndrome: Another phase II trial (NCT02724579) studies the effects of reduced CSI and chemotherapy (no vincristine during radiotherapy and reduced-dose maintenance chemotherapy) on average-risk WNT-activated MBs defined by positive nuclear beta-catenin expression (by IHC), CTNNB1 mutations, and absence of MYC and MYCN amplifications (by FISH).