Moreover, to further confirm, tumor lesions dissected from nude mice in the three different groups we set were immunostained for cleaved caspase 3 and Ki-67, showing that expression of cleaved caspase 3 was higher in KO + Afatinib group, relative to controls; Contrary to cleaved caspase-3, staining of Ki-67 was lower in KO + Afatinib group compared with controls (Fig. 4f). Here, MKI67 is linked to neoplasm.