Comparing the two different cancer cell lines of this study, SKBR-3 and MCF-7, we showed that untreated SKBR-3 cells, as HER2+ belongs to highly metastatic breast cancer cells with an aggressive metastatic phenotype, and therefore the slope of the curve of the spreading experiment increased more rapidly than MCF-7 cells. This evidence concerns the gene ERBB2 and breast cancer.