After stratifying samples according to the International Neuroblastoma Staging System (INSS) stages 1, 2, 3, 4, or 4S, detection of global HDAC transcripts was found to be largely conserved as the disease state progresses, and stage 4 samples had higher mean HDAC transcripts detected relative to stage 1 (Figure 1A). This evidence concerns the gene HDAC9 and neuroblastoma.