E2F3 and lung cancer: The excessive expressions of E2F3 can enhance cell proliferation as there is not enough Rb to bind all E2F3 family members [9], and a number of studies have indicated that E2F3 is overexpressed in lung cancer [10], ovarian cancer [11], and prostate cancer [12], suggesting the abnormal profile of E2F3 is inextricably correlated with tumorigenesis [13].