ALK cooperates with MYCN, activates the MAPK pathways, often dysregulated in relapsing NB, and upregulates the proto-oncogene RET; (iii) overexpression of Lin28B, which negatively regulates miRNA biogenesis by depleting the let-7 family of miRNA, and affects the stability of the AURORA kinase; (iv) loss of 1p and 11p where still undefined tumor suppression genes are located. The gene discussed is MYCN; the disease is neuroblastoma.