When material was available from both sides, the second WT1 hit in contralateral samples occurred independently (each of 11 informative cases). In 12 cases with tumors from both sides, contralateral tumors harbored different WNT activating alterations. Multiple biopsies (3) were available for 32 WT and these carried different CTNNB1/AMER1 mutations within 10 of these tumors
