For example, in highly metastatic and invasive 1-LN prostate cancers, GRP78 interacts with α2-macroglobulin at the cell surface to promote tumor cell proliferation through the ERK1/2 - p38/MAPK - PI3K pathway, and cell survival through the Akt - NF-kB signaling cascade [17]. Here, HSPA5 is linked to prostate carcinoma.