If you use the mouse as your model system, you know that sooner or later your research (or the journal reviewers) will require that you “make a mouse.” By now there are hundreds if not thousands of plasmids/gene targeting constructs that have been made by other laboratories, and thanks to Addgene, you can seek out those resources yourself. Addgene is a nonprofit organization that facilitates the sharing of plasmids among researchers by allowing scientists to deposit and order plasmids through their website. Although ordering plasmids costs money, there is plenty of useful information that can be gleaned for free from the website, such as plasmid vector maps and links to the original journal references for each plasmid. Site visitors can search for plasmids in a variety of ways, such as by empty backbones, species of gene, popular plasmids, or vector type. Additionally, one can search by the depositing scientist, browsing either by recent deposits or the scientist’s country.