[{"from": "human", "value": "Describe this molecule. [C][C][/C][=Branch2][Ring1][=C][=C][Branch1][=Branch2][\\C][=C][C][=C][C][=C][Ring1][=Branch1][/C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][O][C][C][N][Branch1][C][C][C][/C][=C][C][=C][C][=C][Ring1][=Branch1]"}, {"from": "gpt", "value": "The molecule is only found in individuals that have used or taken this drug. It is one of the selective estrogen receptor modulators with tissue-specific activities. Tamoxifen acts as an anti-estrogen (inhibiting agent) in the mammary tissue, but as an estrogen (stimulating agent) in cholesterol metabolism, bone density, and cell proliferation in the endometrium. Tamoxifen binds to estrogen receptors (ER), inducing a conformational change in the receptor. This results in a blockage or change in the expression of estrogen dependent genes. The prolonged binding of tamoxifen to the nuclear chromatin of these results in reduced DNA polymerase activity, impaired thymidine utilization, blockade of estradiol uptake, and decreased estrogen response. It is likely that tamoxifen interacts with other coactivators or corepressors in the tissue and binds with different estrogen receptors, ER-alpha or ER-beta, producing both estrogenic and antiestrogenic effects."}]