Selective Human ER Partial Agonists (ShERPAs), also known as selective estrogen mimics (Fig. 1), are novel benzothiophene [raloxifene (Ralox) or arzoxifene] derivatives with nanomolar potency designed to treat endocrine-resistant BC (Molloy et al., 2014; Xiong et al., 2016). The gene discussed is ESR1; the disease is breast cancer.