We then selected gene sets that were either upregulated (associated with tumor progression) or downregulated (associated with ganglion differentiation) during tumorigenesis.25 The resulting trajectory began with a small cluster of cells (state 1) and branched into 2 arms: the left arm, consisting of ganglion cells (state 2), and the right arm, which comprised MYCN+ neuroblasts (state 3) (Figure 3A and Supplementary Figure S3A). This evidence concerns the gene MYCN and neoplasm.