Evidence is strongest from research in epithelial ovarian cancer demonstrating that ET-1 stimulated ETA-mediated β-arrestin signalling leads to activation of the oncogenic mediator NF-κB [21] and that β-arrestin-1 epigenetically regulates ET-1-induced β-catenin signalling [22], [23] both contributing to tumour cell proliferation, invasion and metastasis. Here, EDN1 is linked to neoplasm.