TREX1 and small cell lung carcinoma: Because H69 cells were established from a patient with SCLC previously treated with chemotherapy, we also tested this in DMS114 cells, a cell line derived from an untreated patient with SCLC, and confirmed that etoposide treatment also increased TREX1 expression in DMS114 cells (Fig. 1G; Supplementary Fig. S1A).