TBXA2R and atherosclerosis: Male sex retained significance after multivariable adjustment; testosterone is known to up-regulate platelet thromboxane A2 receptor density and augment aggregation (20) Intracranial atherosclerosis predicted infarction despite minimal large-artery stenosis in most patients, underscoring the “branch-occlusive” model in which ostial plaques obstruct perforating arteries or create platelet-rich micro emboli (21).