Through forming complexes with specific cell surface proteins, sGRP78 regulates signal transduction of cancer cells, such as the α2-macroglobulin-induced signal [39], TGF-β signaling [40, 41], Ras/MAPK and PI3K/AKT signal pathways [9, 10, 15], Smad2/3 pathways [27], and the mTORC1 and mTORC2 signaling pathways [42], leading to cancer growth and metastasis. This evidence concerns the gene SMAD2 and cancer.