SMAD4 and neuroblastoma: Kaplan–Meier survival plots of 102 well-defined NB cases derived from R2 microarray analysis and visualization platform revealed that patients with high Smad4 expression (P = 3.8 × 10−3), low LEF1 levels (P = 2.4 × 10−4), or low HPSE expression (P = 3.4 × 10−3) expression had greater survival probability (Fig. 6h), which was further validated by different NB cohorts derived from R2 database (Supplementary Fig. S6).