Schematic outline showing potential cooperation between HER-2 and EBV oncoproteins in human gastric cancer initiation and/or progression. We note that HER-2 and EBV oncoproteins share various downstream-signaling pathways, including SRC/β-catenin, PI3k/Akt/mTOR and RAS/MEK/ERK; thus, HER-2/EBV activation pathways could initiate cancer development and/or enhance malignancy progression via the deregulation of cell differentiation (EMT), proliferation, apoptosis and angiogenesis.