The KRAS gene has a high mutation rate in patients with colorectal cancer and lung cancer, and confers the resistance to epidermal growth factor receptor (EGFR), tyrosine kinase inhibitors (TKIs), and EGFR monoclonal antibody agents (Chen et al., 2013; Li et al., 2014; Leiser et al., 2015; Hsu et al., 2016). The gene discussed is EGFR; the disease is colorectal cancer.