Abstract
Neuroblastoma (NB) is a common extra-cranial solid malignancy of childhood. NB displays several clinical and biological features as well as many indeterminate aspects. Studies attempting to determine a prognostic factor in NB have been performed for a long time. Recent studies have focused on the anaplastic lymphoma kinase (ALK) gene. ALK mutations are one of the most prevalent and important biological disorders in NB. The presence of ALK mutations contributes to a more malignant character in NB. However, there is a limited number of studies on the clinical relevance of the expression of ALK or of its mutations. Th e elucidation of gene expression analyses in ALK can guide in the identification of risk groups and selection of treatment protocols. There is a need for further studies, as it is important to define patients eligible for use of ALK inhibitors.