EGFR and small cell lung carcinoma: We performed single-cell RNA sequencing (scRNA-seq) on epidermal growth factor receptor (EGFR) mutant PC9 non–small cell lung cancer persister cells, derived from 10 days of treatment with EGFR inhibitor erlotinib, which were subsequently treated with GPX4 inhibitor RAS-selective lethal 3 (RSL3) for 24 hours resulting in partial death and effectively purifying surviving persister cells.