HACE1 and Wilms tumor: Sequencing of clone 10 (Figure 1b) identified an out-of-frame insertion in Exon 22 of the murine HACE1, which has previously been identified as an E3 ubiquitin ligase lost in sporadic Wilms' tumor patients (Figure 1c).9 The out-of-frame insertion in clone 10 resulted in a decrease in HACE1 mRNA expression compared with parental cells (Figure 1d).