Afatinib is known as a first-line FDA-approved drug for the treatment of metastatic non-small cell lung carcinoma (NSCLC) with EGFR mutations, which is a tyrosine kinase inhibitor (TKI) not only against EGFR mutations but also inhibit HER2-overexpressed breast cancer. Here, ERBB2 is linked to non-small cell lung carcinoma.