PARP1 and small cell lung carcinoma: Overexpression of PARP1 indicates good therapeutic response for inhibiting PARP in SCLC.16 Studies have shown two main mechanisms of PARP inhibitors to exert their effect: trapping the enzyme to the SSBs and preventing PARylation and binding of PARP to DNA.17 Many PARP inhibitors, such as olaparib, talazoparib (BMN-673), pamiparib (BGB-290), and veliparib (ABT-888) are undergoing active clinical investigation in SCLC.18–22