ALK and inflammatory myofibroblastic tumor: Chromosomal rearrangements are frequently observed in IMT, including ALK rearrangement, a genetic abnormality driving tumor cell proliferation in the form of fusions of various chaperone genes such as TPM3-ALK, TPM4-ALK, CLTC-ALK and EML4-ALK (56,58); furthermore, the diversity of recombination patterns may be closely associated with clinical heterogeneity (58).