This month’s issue of CSH Protocols features an article by Andrew Salinger and Monica Justice, detailing a technique for Mouse Mutagenesis Using N-Ethyl-N-Nitrosourea (ENU) (article is freely available as one of our featured protocols). Back in the ancient days of my graduate school work, the idea of doing large scale forward genetics in mouse was unthinkable. Who had the space, let alone the funding and personnel to keep and track all of those cages? It was always one of those reasons we grumbled about the Drosophila labs, and the incredibly cool tools they had at their disposal. Over the years, the techniques were refined, and now, according to Justice, screens like this are an “established as part of a mouse geneticist’s toolkit,” and can be effective even in labs with very limited amounts of mouse space. So it’s nice to see this incredibly productive method readily available for use in mouse. Now if we can just do something about that pesky internal development that’s so limiting to imaging experiments…..