Binding between EGF and EGFR forms a dimer that is phosphorylated or transphosphorylated to produce biological signals, then activating several downstream signal transduction pathways and transducing them inside cell nuclei.20 It has previously been reported that EGFR is highly expressed in malignant tumors instead of in normal tissues.21 Similarly, the observation group herein had significantly higher percentage and positive rate in EGFR expression than those of the control group (P<0.05). Here, EGF is linked to cancer.