CDC27 and neuroblastoma: In view of the endogenous expression level of CDC27 in the NB cell lines above, SK-N-SH and SH-SY5Y cells were selected to transiently knock down or overexpress CDC27 using siRNA (siCDC27, siNC as a negative control) and CDC27-carrying plasmids (pcDNA3.1-CDC27, pcDNA3.1 as a negative control), respectively.