Phil Hogg discovered a unique mechanism of control of protein function that operates across all biological systems and lifeforms. This involves a subset of disulphide bonds thought only to act as covalent modifiers of protein structure functioning as molecular switches to allosterically regulate protein function when cleaved. He developed a novel classification scheme for disulphides and uncovered a conformational signature for the allosteric bonds that underpins their facile nature. He has shown that thrombosis as well as immune responses and viral infections are critically regulated by this previously unrecognised chemical modification.