Several clinical trials are ongoing for testing SRA-737 as monotherapy or combined with gemcitabine in patients with a variety of solid tumors including SCLC (NCT0279964, NCT02797977).31 Furthermore, a recent study showed that targeting the two DDR proteins, PARP or CHK1, remarkably increased expression of PD-L1. Here, CD274 is linked to small cell lung carcinoma.