PTPMT1fl/+ mice were generated in our previous study (20 (link)). Nestin-Cre+ (21 (link)), Nestin-Cre+-Esr1 (25 (link)), PCP2-Cre+ (22 (link)), Atoh1-Cre+ (23 (link)), CAG-Cre+-Esr (24 (link)), and p53+/− (36 (link)) mice were purchased from the Jackson Laboratory. Mice of the same age, sex, and genotype were mixed and then randomly grouped for subsequent analyses (investigators were not blinded). All mice were kept under specific pathogen–free conditions in Division of Animal Resources at Emory University. All animal procedures complied with the National Institutes of Health Guide for the Care and Use of Laboratory Animals and were approved by the Institutional Animal Care and Use Committee.