Considering that both Zfhx3 and ERβ are necessary for proper development of mouse prostates, both possess a tumor suppressor activity in prostate cancer, ZFHX3 interacts with ERα to modulate its functions, and ERβ is highly homologous to ERα; it is reasonable to propose that ZFHX3 and ERβ interact with each other to modulate cell proliferation and tumor growth of prostate cancer cells. This evidence concerns the gene ESR2 and Familial prostate cancer.