Flowcytometry may also be used to investigate abnormalities in the collagen (GpVI and GpIa/IIa), thrombin receptors (PAR-1) and Glanzmann thrombasthenia (GpIb, GpIIb and GpIIIa) (1B). The gene discussed is F2R; the disease is Glanzmann thrombasthenia 1.