In small cell lung cancer (SCLC), PARPi was demonstrated to trigger the activation of cytotoxic T lymphocytes (CTL) via upregulating the STING/TBK1/IRF3 innate immune pathway, and to increase the expression of chemokines such as C-X-C motif chemokine ligand 10 (CXCL10) and C-C motif chemokine ligand 5 (CCL5) [330]. Here, IRF3 is linked to small cell lung carcinoma.