EGFR and non-small cell lung carcinoma: Insertions in exon 20 (Ex20ins) of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are relatively insensitive to first‐ and second‐generation EGFR‐tyrosine kinase inhibitors (TKIs) in non‐small cell lung cancer (NSCLC).