Overexpression of β-hCG promoted cell migration and invasion in ES-2 and SKOV3 ovarian cancer cell lines by transwell assays and wound healing in vitro and in a nude mouse model in vivo, while silencing β-hCG resulted in the opposite effect.[13] The effect of β-hCG was mediated by the activation of extracellular signal-regulated kinase 1/2 and matrix metalloprotease-2.[11] Overexpression of β-hCG also increased the expression of mesenchymal cell markers and decreased the expression of epithelial cell markers, thus improving EMT and metastasis of ovarian cancer. Here, MAPK3 is linked to ovarian cancer.