HSPA5 and hepatocellular carcinoma: MTT assay showed that rhGRP78 protein maintained cell viability in the presence of sorafenib in PLC (sorafenib versus rhGRP78/sorafenib: 12.76 ± 3.81% versus 47.62 ± 6.63%) and SMMC7721 cells (sorafenib versus rhGRP78/sorafenib: 38.27 ± 4.35% versus 59.34 ± 5.87%) (Figure 2B, 2C), indicating that secreted GRP78 decreased the sensitivity of HCC cells to sorafenib.