Transposons have been promising elements for gene integration, and the Sleeping 
Beauty (SB) system has been the major one for many years, although there have 
been several other transposon systems available, for example, Tol2. However, 
recently another system known as PiggyBac (PB) has been introduced and developed 
for fulfilling the same purposes, for example, mutagenesis, transgenesis and 
gene therapy and in some cases with improved transposition efficiency and 
advantages over the Sleeping Beauty transposon system, although improved 
hyperactive transposase has highly increased the transposition efficacy for SB. 
The PB systems have been used in many different scientific research fields; 
therefore, the purpose of this review is to describe some of these versatile 
uses of the PiggyBac system to give readers an overview on the usage of PiggyBac 
system.