Fortunately, our results clearly showed that the GBP-SubA was able to enter into the tumor cells, and the amount of GBP-SubA in cells was increased along with the enhanced cell surface GRP78, furthermore, blocking NH2-terminal of GRP78 with antibody could reduce GBP-SubA entry efficiency and reverse the proliferation-inhibition and the apoptosis-induction effects of GBP-SubA. Here, HSPA5 is linked to neoplasm.