Likewise, alterations in HR pathway genes such as BRCA1, ATM, PALB2, etc. may suggest sensitivity to poly (ADP-ribose) polymerase (PARP) inhibitors olaparib and talazoparib, both of which are being investigated for treating HR pathway-mutated (NCT03009682) or BRCA1-mutated SCLC 31. Here, BRCA1 is linked to small cell lung carcinoma.