Histologically, tumors were characterized by a defined tumor border (Figure 5A), lack of fibrillary collagen (Figure 5B), remarkable cellular proliferation (Figure 5C), lack of type IV collagen in the tumor parenchyma (Figure 5D), diffuse glutamine synthetase expression pattern (Figure 5E), and a lack of HBsAg expression (Figure 5F). Here, GLUL is linked to neoplasm.