DNA damage repair (DDR) inhibition and immune checkpoint blockade (ICB) have each individually shown modest clinical activity in small cell lung cancer (SCLC). Recently, Sen and colleagues (Cancer Discov. 2019;https://doi.org/10.1158/2159-8290.CD-18-1020) demonstrated that DDR inhibition can activate the stimulator of interferon genes (STING) innate immune pathway, providing strong rationale for combining DDR inhibition and ICB to treat SCLC.