Because of their rarity, prospective clinical trials of ALK inhibitors as treatment for ALK-arranged sarcomas have been difficult to perform, but due to the Children’s Oncology Group’s perseverance, phase I and II crizotinib trials were completed and high responses with good prognoses were certified for pediatric IMT patients; in the phase II trial, complete response rate was observed in five of 14 (36%) patients [93,94]. This evidence concerns the gene ALK and inflammatory myofibroblastic tumor.