Recently, some findings have demonstrated that polymorphisms in the estrogen receptor (ER) [2, 3], type I collagen (COL1) [4–6], vitamin D receptor [7, 8], and low density lipoprotein receptor-related protein 5 (LRP5) [9, 10] genes are highly associated with osteoporosis. The gene discussed is ESR1; the disease is osteoporosis.