The data show that HER2-positive breast cancer cells are sensitive to GNF-5837 and that viability is reduced in a dose-dependent manner for all cell lines: SK-BR-3 (IC50 = 2.59 μM, Figure 4A), BT-474 (IC50 = 4.66 μM, Figure 4B), MDA-MB-453 (IC50 = 4.69 μM, Figure 4C) and JIMT-1 (IC50 = 15.31 μM, Figure 4D). This evidence concerns the gene ERBB2 and breast carcinoma.