Les-6287, Les-6294, and Les-6328 compounds were evaluated for their impact on the metabolic activity and survivability of breast carcinoma cells of MCF-7 and T-47D (ER+, PR+, HER2-), MDA-MB-231 and 4T1 (ER-, PR-, HER2-), and HCC1954 (ER-, PR-, HER2+) lines, and normal breast cells of the MCF-10A line. The gene discussed is ERBB2; the disease is breast carcinoma.