DKK1 and ovarian cancer: We hypothesize that in normal ovarian epithelia, E2F1 turns on expression of DKK-1, which in turn inhibits the WNT pathway, which ultimately stops the expression of cell-cycle genes, whereas in ovarian cancer, disruption of E2F1 regulation of DKK1 results in loss of DKK1 expression and corresponding activation of the WNT pathway, ultimately resulting in activation of cell-cycle genes.