Although we have only used a single antigen to show proof-of-concept of our AnExIL vaccination platform, mixtures of antigens can be expressed inside AnExILs by simply mixing pDNAs encoding different antigens. Although different antigens will have different levels of expression in cell-free expression systems, in general, the expression levels are high enough for the purpose of vaccination, where only microgram quantities of proteins are required. In fact, membrane proteins which are often difficult to produce in bacteria show remarkably high levels of expression in prokaryotic cell-free systems in the presence of liposomes (Junge et al. 2010; Goren et al. 2009; Kuruma et al. 2010; Moritani et al. 2010; Nozawa et al. 2010; Reckel et al. 2010) . Besides DNA encoding antigens, a variety of genetic inputs can be used in order to control the type of immune response provoked. For example, genetic adjuvants, such as chemokines or cytokines may be coexpressed inside the AnExILs in order to enhance the influx of immune cells at the site of injection and uptake of AnExILs by antigen presenting cells. As such AnExILs form an excellent synthetic biology platform for genetic programming using standard biological parts (Canton et al. 2008; Knight 2003) .