Thus, MDA-MB-231 and 4T1 triple-negative breast carcinoma cells, MCF-7 and T-47D estrogen and progesterone receptors positive, HER2 negative, and HCC1954 HER2 positive breast carcinoma cells were sensitive to the action of Les-6287, Les-6294, and Les-6328 with IC50 levels of 1.37–21.85 μM at their treatment for 24 and 48 h. This evidence concerns the gene ERBB2 and breast carcinoma.