While working as a postdoctoral researcher with Jack Strominger at Harvard, we first described an NK cell immune synapse [PNAS. 1999; 96:15062-7]. My laboratory has since continued to probe functions and mechanisms for the NK cell synapse e.g. J Exp Med. 2001; 194:1507-17, J Exp Med. 2004; 199:1005-10, summarised in Trends Immunol. 2004; 25:323-7 and 2002; 23:356-63 and for a more general audience in Scientific American, 2006; 294:48-55. Most recently, we reported microclusters of inhibitory signalling at synapses [J Cell Biol. 2006; 174:153-61] and found that segregation of proteins at synapses can be controlled by their cell surface density [J Immunol. 2006; 177:6904-10].