ERVW-1 and cancer: WB assays also confirmed that the expression of cell fusion-related proteins, including p-ERK1/2(mouse), p-ERK1/2(rabbit), ERK1/2, P38 MAPK, β-catenin, GCM1, syncytin-1, and ASCT-2, increased compared to that in control cancer cells (Figure 4A), and the differences were statistically significant (Figure 4B).