Compound cross with p53-deficient mice (Prx1Cre-mediated p53 deletion) synergized in osteosarcoma formation.12, 13 Furthermore, data from six independent laboratories presented 16 different Cre-mediated transgenic approaches to generate an Ewing Sarcoma mouse, which failed owing to high apoptosis and toxicity upon EF expression in multiple cell types.14 Here, TP53 is linked to Ewing sarcoma.