MDM2 and embryonal rhabdomyosarcoma: For example, in human embryonal rhabdomyosarcoma (ERMS), a common pediatric cancer of muscle, the TP53 locus is mutated or deleted in 16% of tumors, while transcriptional activity is altered in >30% of tumors, either through direct locus disruption or MDM2 amplification (Chen, 2013; Seki et al., 2015; Shern et al., 2014; Taylor et al., 2000).