MYCN and neoplasm: Indeed, TH-MYCN+/+Nudt1null mice displayed a remarkable delay in tumor development compared to their TH-MYCN+/+ littermates, with approximately 60% of TH-MYCN+/+Nudt1null mice that lived beyond 100 days (and 5 mice, having been tumor-free for >850 days, are still alive), a time point at which all TH-MYCN+/+ mice had died (Fig. 4f).