GPC3 and susceptibility to pneumonia measurement: Recently, our group found that the serum level of Glypican-3 (GPC3), a proteoglycan anchored to cell surface by glycosyl-phosphatidylinositol, was significantly higher in the circulation of patients with severe pneumonia, as compared with healthy control, and increased even more significantly in patients with severe pneumonia accompanied with ARDS than those with severe pneumonia alone [3].