GP6 and B-cell chronic lymphocytic leukemia: Further, unlike immune-related thrombocytopenia where anti-platelet antibodies acting at the FcγRIIa receptor markedly increase GPVI shedding resulting in lower surface expression and increased levels of sGPVI in plasma [76,79,80], in untreated CLL the plasma sGPVI levels were in the normal range, suggesting observed low platelet GPVI was unlikely to be the result of increased shedding.