Table 22.1 Comparison of sleeping beauty and piggyBac properties, TSS (transcriptional start sites):

There are two types of gene delivery: (i) “ cis ” transposon mediated gene delivery (ii) “ trans ” transposon mediated gene delivery. The transposase enzyme is carried by the same plasmid having the same backbone of the transposon. The same vector background is used to carry transposase and the transposon which carry the gene of interest (GOI). This is known as “ cis ” delivery. In “ trans ” delivery a separate circular plasmid carries the enzyme transposase. The transposase and transposon are delivered either in “ cis ” or in “ trans ” form in gene therapy purposes. But transposition efficiency is more in the case of “ cis ” configuration.