ALK and neuroblastoma: The three genes MYCN [30], ALK [31], and PHOX2B [32] have been directly linked to NB pathogenesis; MYCN is amplified in a subgroup of aggressive metastasizing tumours, activating mutations of ALK or amplification is seen in approximately 7% of sporadic cases [33,31-37], and PHOX2B is mutated in a subset of familial cases and in a small percentage of sporadic cases [32,38].