HSPA5 and neoplasm: For in vivo xenotransplantation assay, we observed that 10000 GRP78- cells did not induce tumor formation but 100 GRP78+ HNSCCs resulted in the generation of visible tumors 4 weeks after injection in xenotransplanted mice (Figure 2G, H, and 2I, Additional file 2D, 2E and 2F).