To resolve the levels of platelet GPVI-dimer and total GPVI (monomeric and dimeric GPVI on the platelet surface) in patients with stroke, we used the GPVI-dimer–specific antibody 204–11 Fab [5] and HY101 [15], an antibody that recognizes both GPVI-monomers and -dimers. The gene discussed is GP6; the disease is Stroke.