CDK2 and neuroblastoma: To refine our analysis, we included additional genes: inhibitor targets such as CDK2 and CDK9, neuroblastoma-associated genes, ALK and PHOX2B, along with the two upregulated genes from the combination, CRABP2 and CYP26B1. Using MCL clustering [24], we found four major clusters (yellow, red, mustard green, and green) of gene interactions.