The association between high ERβ1 and ERβ2 protein expression and ERα-negative BCa, and between ERβ1 and ERβ5 protein expression and TNBC with >15% Ki-67 positivity (Table 4) suggests a potential role of ERβ in tumor growth in ERα-negative BCa and TNBC. The gene discussed is MKI67; the disease is neoplasm.