DLL3 and small cell lung carcinoma: Because DLL3 is largely expressed in SCLC and regarded as a potential biomarker for response to Rova-T treatment (8), we aimed to investigate DLL3 expression in chemorelapsed SCLC samples and to compare its expression with matched chemonaive SCLC samples, correlate its expression with clinicopathological data, and perform survival analysis stratified according to DLL3-high or DLL3-low status and dynamics of DLL3 expression during the course of therapy.