MYF5 and epithelioid sarcoma: Synchronous Smarcb1 inactivation, pathognomonic for malignant rhabdoid tumors (MRT) and epithelioid sarcomas (EpS), accelerated tumor formation to a mean latency of 173 days with 100% penetrance and 17% bilateral tumor fraction, which is significantly more efficient compared to a previously reported Myf5-Cre-mediated Smarcb1-inactivation model exhibiting 40% and latency longer than 12 months36.