TP53 and neuroblastoma: Inversely, knockdown of NGFR strikingly elevated the level of endogenous p53 and that of its target genes p21 and PUMA in human p53-containing H460, HepG2, neuroblastoma SK-N-SH, melanoma SK-MEL-103 and SK-MEL-147 and HCT116 p53+/+ cell lines (Figure 3B), whereas did not affect PUMA expression in HCT116 p53-/- cells (Figure 3—figure supplement 1).