(A) Total PARP expression was higher in neuroendocrine tumors (SCLC, LCNEC, atypical carcinoid, and typical carcinoid) than in lung squamous cell carcinoma and adenocarcinoma. ‡p=0.0002 (SCLC versus squamous tumors), †p=0.001 (LCNEC versus squamous), *p<0.0001 (SCLC or LCNEC compared to adenocarcinoma). (B) Representative PARP1 IHC staining for each tumor type.