EGFR and non-small cell lung carcinoma: The T790M mutation is a known mechanism of acquired resistance to first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, in NSCLC patients who are subsequently treated with the third-generation EGFR-TKI AZD9291 (osimertinib) (Leonetti et al., 2019; Roskoski, 2022).