TREX1 and small cell lung carcinoma: However, we also evaluated TREX1 expression in SCLC cell lines grouped as “pre” (cell lines derived from patient prior to chemo) or “post” (cell lines derived from patients previously treated) and observed that TREX1 expression tended to be higher in “post” cell lines suggesting that, beyond transcriptional subtypes, TREX1 upregulation might be an adaptive strategy for SCLC cells to adapt and survive to the continuous accumulation of cytosolic DNA derived from DNA-damaging agents (Supplementary Fig. S1E).