HSPA5 and breast cancer: In breast cancer cells, IGFBP3 promotes survival through a number of mechanisms, including 78-kDa glucose-regulated protein (GRP78)-mediated autophagy [25], promotion of DNA repair through formation of a nuclear complex with the epithelial growth factor receptor (EGFR) and the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) [26], and through transactivation of the EGFR via the sphingosine-1-phosphate (S1P) pathway [27].