EGFR and non-small cell lung carcinoma: Unlike NSCLC tumors with epidermal growth factor receptor gene (EGFR)-sensitizing mutations (exon 19 and exon 21), which respond to treatment with the approved tyrosine kinase inhibitors (TKIs) afatinib, erlotinib, and gefitinib [2], NSCLC tumors with EGFR exon 20 insertion (ex20ins) mutations are difficult to treat, demonstrating low response rates to those agents [3].