LMO3 formed a complex with neuronal-specific basic helix-loop-helix (bHLH) transcription factor HEN2, which was also expressed at higher levels in unfavorable neuroblastoma than favorable one, raising a possibility that LMO3 may form a complex with HEN2 and play an important role in genesis and development of neuroblastoma through transcriptional regulation of as yet unidentified target gene(s). This evidence concerns the gene NHLH2 and neuroblastoma.