PIF1 and neuroblastoma: We noted that our analysis based on the primary NB tissues reproduced some known markers for NB prognosis and high-risk, including CKS2 that was considered a prognostic marker of various tumors (44), PDK1 that could provide significant hints for high-risk NB patients (45), and PIF1, one Myc-target gene, that could significantly repress tumor upon knockdown (46).