Furthermore, the random forest model successfully stratified patients with MYCN non-amplified neuroblastoma into distinct subgroups 1, 2, and 3 with significant differences in survival across five independent validation sets (GSE49711 [31], TARGET Microarray [32], TARGET RNA-seq, Westermann ALK cohort [33] and Stefan Hüttelmaier cohort [34] respectively) (Fig. 7a, b; Supplementary Table 11). Here, ALK is linked to neuroblastoma.