By binding to both HER2 and EGFR receptors, lapatinib prevents activation of important pro-cancer pathways such as Erk/MAPK (extracellular-signal-regulated kinase/mitogen-activated protein kinase) and PI3K (Phosphatidylinositol 3-kinases) which have vital roles in cell proliferation and survival [8,9]. This evidence concerns the gene ERBB2 and cancer.