ALK and neuroblastoma: These neuroblastoma cell lines are all ALK gain-of-function in nature, containing either an activated ALK mutation (ALKR1275Q, CBL-GA; ALKF1174V, CLB-GE; ALKF1174L, Kelly) or overexpressing an ALK receptor with an extracellular domain deletion (CLB-BARΔexon 4–12), and express different levels of MYCN (Fig. S3) 38,39.