Groups including ours previously reported that ER-β gene (ESR2) cytosine-adenine (CA) repeat polymorphism (ESR2-CA) [13] in the germline affected the colon cancer risk in postmenopausal women, but not rectal cancer risk, or colon cancer risk in men and premenopausal women [14,15,16]. Here, ESR2 is linked to rectal cancer.