Approaches that use in vivo chemistry to enable non-invasive molecular imaging and therapy are much sought after. Taking the recent achievements in pretargeted radioimmuno-imaging and -therapy in mice as a starting point, the Tagworks team discuss how the application scope of this approach can eventually be extended towards humans. Read "Pretargeted imaging using bioorthogonal chemistry in mice" in Current Opinion in Chemical Biology 2014, 21:161-169. doi:10.1016/j.cbpa.2014.07.023