While we noticed some discrepancies in expression between in vitro and in vivo, cell cycle and p53 relevant genes, i.e., CCNB1, PLK1, MYC, CDC20 were similarly downregulated in both conditions, supporting the hypothesis that indeed tumor cell killing features of this gene suicide system are induced via disruption of the cell cycle, which also translated onto the protein level.PLK1, which phosphorylates CCNB1 (32), is overexpressed in several cancers (33). The gene discussed is PLK1; the disease is cancer.