Decreased XRCC1 expression due to gefitinib, a selective epidermal growth factor receptor-tyrosine kinase inhibitor and Hsp90 inhibitor led to synergistic cytotoxic effects on non-small cell lung cancer cells.474 We screened the clinical trials related to XRCC1 using the keyword “XRCC1” (https://clinicaltrials.gov/). The gene discussed is XRCC1; the disease is non-small cell lung carcinoma.