Glypican-3 (GPC3), a member of the glypican family of heparan sulfate proteoglycans (HSPGs) which are attached to the cell surface by a glycosylphosphatidylinositol (GPI) anchor (1), is specifically expressed in ovarian clear cell carcinoma (OCCC) (2,3), hepatocellular carcinoma (HCC) (4,5), lung cancer (6) and melanoma (7). The gene discussed is GPC3; the disease is lung cancer.