Unlike most extant mouse models of STS, this model further recapitulates the human disease in that its genetics reflect the functional loss of TP53 and gain of CCNE1, which were identified among the most frequently occurring genetic and transcriptional defects in the complex-karyotype soft-tissue sarcomas (The TCGA Research Network, Cell 2017). The gene discussed is CCNE1; the disease is telomere syndrome.