In order to maintain both plasmids to ensure that the module can be implemented successfully, and to kill the engineered VNP20009 when the condition of illness improved after tumor regression, we have designed a "logical suicide circuit" to maintain two plasmids in the project and to induce engineered bacteria to commit suicide through intake of doxycycline after the end of the mission. We introduced the "logical suicide circuit" in two plasmids (Figure 1). Parts numbers are BBa_K4737017 and BBa_K4737018.

For more details, refer to Design, Results, Engineering and Model.

Name	Basic/Composite	Short Description	Long Description
BBa_K4737017	Composite	prpsM::tetR	To express tetR constitutively
BBa_K4737018	Composite	pLtetO::LacI-T7 promoter::Lac operate-Sok-trp promoter::trp operator-Mok/Hok	To express LacI controlled by tetR, to express Sok controlled by LacI, and to express Mok protein and Hok protein constitutively