Recently, Khongsti and co-workers found that human BC cells (MDA-MB-435 and MDA-MB-231) treated with genistein showed a reduction in osteopontin (OPN) secretion associated with increased phosphorylation of ERK1/2 and mitogen-activated protein kinase kinase 1/2 (MEK1/2) and upregulation of a member of the NAD (+)-dependent histone deacetylase family, namely SIRT1. This evidence concerns the gene MAPK1 and breast cancer.