As we know, studies have demonstrated that PI3K-AKT pathway activity is directly linked to the proliferation and growth of HER2-overexpressing cancer cells and trastuzumab mainly exerted its anti-tumor in inhibiting the HER2-PI3K-AKT pathway (Pal and Mandal, 2012; Li et al., 2013; Han et al., 2014). The gene discussed is ERBB2; the disease is cancer.