In 2021, in line with the campaign of Choosing Wisely to minimize non-beneficial use of resources in healthcare [7], the American Society of Clinical Oncology recommended that SLNB is not required for patients older than 70 years with small (T1) and cN0 invasive breast cancer that is estrogen receptor positive (ER-positive) and HER2-negative [8]. The gene discussed is ESR1; the disease is invasive breast carcinoma.