PHLDA1 and neuroblastoma: The decreased cytotoxicity of doxorubicin was observed following PHLDA1 silencing in the S6 and S17 clones of CHP-134 neuroblastoma cells compared with that in the control cells, and a statistically significant decrease in ATP levels was detected only at the highest concentration tested (150 nM) (Supplementary Fig. S11 online).