EGFR and neoplasm: Immunohistochemistry of paraffin-embedded tissue sections from Hep3B, PLC/PRF/5, and HepG2 xenografts showed that Hep3B xenografts have extensive staining of EGFR, whereas PLC/PRF/5 xenografts showed regional positive staining, and HepG2 tumor did not show any positive regions (Figure 3(b)).