Jamie Rossjohn has had a profound impact on our understanding of immune recognition. By bringing the power of structural biology to bear, he has explained the pre-T-cell receptor (TCR) self-association in thymocyte ontogeny, provided novel insights into how TCRs interface with viral peptides bound to polymorphic HLA glycoproteins, and illuminated the aberrant T-cell reactivity that leads to autoimmunity and drug/food hypersensitivities. From the aspect of innate immunity, he pioneered the structural definition of Natural Killer cell specificity and defined the lipid-based immunity mediated by Natural Killer T-cells. Functioning at the cutting edge of immunology, Rossjohn has a stellar international reputation.