ESR1 and breast cancer: Similarly, it is associated with an estimated42,780 deaths, comprising 530 male deaths and 42,250 female deaths(Figure ). It is the most common cancer in women and theleading cause of cancer-related mortality in 112 countries., It is divided into three primary types: estrogen receptor-positive(ER+), human epidermal growth factor receptor 2-positive (HER2+) andtriple-negative breast cancer (TNBC). Evenwith advances in the early detection and treatment of BC, metastasisis still the most common cause of death for patients with this disease,and the 5-year survival rate is less than 30%.