In this study, we have shown that FKA preferentially inhibits the growth of HER2-overexpressing breast cancer cell lines versus those with less HER2 expression by downregulating the expression of Myt1 and Wee1 kinases leading to reduced phosphorylation levels of Cdc2, which then leads to G2M arrest and apoptosis. The gene discussed is MYT1; the disease is breast cancer.