ESR1 and breast carcinoma: To investigate the antitumor effects of SC-1 and SC-43 on breast cancer cells, we assessed the antiproliferative activity of sorafenib and its analogues in a panel of six human breast cancer cell lines: TNBC cells HCC-1937, MDA-MB-231 and MDA-MB-468; HER2-overexpressing cells MDA-MB-453 and SK-BR3; and estrogen receptor positive cells MCF-7 (Figure 1E).