Formation of clots to prevent blood loss is initiated by the platelet receptors, glycoprotein (GP)Ib-IX-V and GPVI. Unfortunately, there is a gap in our knowledge regarding the events immediately following activation of these receptors and the known downstream signalling. We have identified a novel binding partner for these platelet receptors, which we believe links reactive oxygen species to platelet signalling events. This opens new avenues for therapies to prevent aberrant clotting.