GPC3 and neoplasm: Immunohistochemical staining for the HCC marker, glypican 3 (GCP3) in livers harboring tumors, demonstrated positive staining in five of nine Casp2C320S and two of four Casp2−/− mice, while the two WT livers with tumor nodules were negative for GCP3, suggesting that these liver tumors were not HCC (Fig. 2G).