Although in vitro proliferation assays did not enable us to identify a specific pediatric indication with a particular susceptibility to regorafenib such as GIST or RET mutated thyroid cancer, we conclude from our in vivo results that regorafenib exhibits significant antitumor activity in a large variety of pediatric malignancies, independent of histological tumor type. This evidence concerns the gene RET and gastrointestinal stromal tumor.