Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Harald von Boehmer describes how he used mice transgenic for T cell receptor αβ to identify T cell receptor–dependent cellular selection and lineage commitment as mechanisms responsible for generating an effective and self-tolerant adaptive immune system.
The idea that NK cells can distinguish aberrant cells by recognizing 'absence of the expected', rather than 'presence of the unexpected' emerged more than 25 years ago. Klas Kärre recapitulates how the idea took shape, and the first five years of experimental work to test its general predictions.