WT1 and Wilms tumor: The genetic aberrations underlying this process are varied and include inactivating mutations of Wilms tumor 1 (WT1) (Huff, 1998; Ruteshouser et al., 2008), Wilms tumor gene found on chromosome X (WTX) (Fukuzawa et al., 2010; Perotti et al., 2008; Rivera et al., 2007), and stabilizing/activating mutations of β‐catenin (CTNNB1) (Koesters et al., 1999; Maiti et al., 2000).