Mutations that lead to EGFR overexpression (known as upregulation) or overactivity have also been reported previously in various cancers including GBC with variable frequencies like squamous-cell carcinoma of the lung (80% of cases), glioblastoma (50%) and epithelial tumours of the head and neck (80–100%) [38]. Here, EGFR is linked to squamous cell lung carcinoma.