There is a need for new therapies that have activity against these types of sarcomas. REOLYSIN® is an unmodified oncolytic reovirus which replicates selectively in ras transformed cells causing cell lysis. Activating mutations in ras or mutations in oncogenes signaling through the ras pathway may occur in as many as 80% of human tumors. Such mutations have been described in many of the common sarcomas of childhood and adults. REOLYSIN® demonstrated excellent anti-tumor activity in vitro and in vivo in childhood sarcoma cell lines.