Lysates of reported TNBC cells (MDA-MB-231, MDA-MB-435, BT549, HCC-38, HCC-1143, and HCC-1937) and nuclear ERα-positive controls (MCF-7, T47D) were subjected to gel electrophoresis and immunoblots with anti-ERβ antibody and anti-ERα antibody. The gene discussed is ESR2; the disease is hepatocellular carcinoma.