HPRT1 and neuroblastoma: Toward these ends, we have used qPCR and Western blotting methods to demonstrate that HPRT deficiency in differentiating human neuroblastoma cells indeed does dysregulate expression of several vital CNS neuronal and developmental signaling pathways in which we had predicted dysregulated expression by GO and GSEA analysis of microarray-based global gene expression analyses of control and HPRT-knockdown human fibroblasts.