In this issue of Mobile Genetic Elements

Because transposons are able to self-excise and self-insert into the genome, they can also be used as a tool for altering gene expression, especially in the case of transposon mutagenesis. Here, Meredith et al. describe a robust transposon mutagenesis system that they have created allowing for the creation of a large range of expression genotypes in S. aureus. This collection has allowed for the selection of compoundresistant transposon insertion mutants and holds future promise for evaluating future novel targets and mechanisms of action in antibacterial therapies (Fig. 1).