Anthony James Pawson CH, OC, OOnt, FRS, FRSC (18 October 1952 – 7 August 2013) was a British-born Canadian scientist whose research revolutionised the understanding of signal transduction, the molecular mechanisms by which cells respond to external cues, and how they communicate with each other. He identified the phosphotyrosine-binding Src homology 2 (SH2 domain) as the prototypic non-catalytic interaction module. SH2 domains serve as a model for a large family of protein modules that act together to control many aspects of cellular signalling. Since the discovery of SH2 domains, hundreds of different modules have been identified in many proteins.