My favorite organic molecule is Tamoxifen which is an antagonist of the estrogen receptor in breast tissue. This molecule was discovered by a pharmaceutical company called AstraZeneca. Not only that this drug is used for cancer treatment, it is also use to treat premature puberty, bipolar disorder, infertility, and gynecomastia. It is my favorite molecule because it is use for hormone therapy for hormone receptor-positive breast cancer in premenopausal women for early and late breast cancer. Few years ago, my mother was diagnosed of stage 3 breast cancer and this drug was used. Due to the effectiveness of this drug with the combination of chemotherapy, radiation and surgery, my mom defeated cancer.