WT1 and Wilms tumor: For instance, homozygous loss of the Wilms tumor driver gene Wt1 was shown to be embryonically lethal in mice (Kreidberg et al., 1993), whereas a specific Wt1 ablation at E11.5 in a small fraction of nephron progenitor cells resulted in Wilms tumor formation (Hu et al., 2011; Berry et al., 2015; Huang et al., 2016).