HSPA5 and breast cancer: Later, cell membrane localization of GRP78 has been identified in human prostate cancer cells [39, 40], breast cancer cells [41], human glioblastoma multiforme cells [42], murine macrophages [43], etc. In addition, overexpression of GRP78 in HEK293 cells stimulates cell membrane relocation [44], suggesting that upregulation of GRP78 in cancer cells may be the primary reason of membrane migration.