ALK and inflammatory myofibroblastic tumor: A phase 2 trial of crizotinib in children with refractory or relapsed ALK-mutant neuroblastoma reported an RR of 15% (3/20);13 in stark contrast, far more objective and sustained responses were observed in ALK-fusion-driven refractory or relapsed anaplastic large cell lymphoma (RR 90%) and inflammatory myofibroblastic tumors (RR 86%)14, highlighting the difference between therapeutic targeting of full-length mutated ALK in neuroblastoma compared to cytoplasmic ALK fusion proteins in other cancers.