The 120 cases of invasive breast cancer were confidently classified as ER-positive (n = 86) vs ER-negative (n = 34), PR-positive (n = 53) vs PR-negative (n = 67), HER2-positive (n = 47) vs HER2-negative (n = 73), and Ki67 low-proliferation (n = 70) vs Ki67 high-proliferation (n = 50). This evidence concerns the gene ESR1 and invasive breast carcinoma.