While Adenomatous polyposis coli (APC) mutations seem to occur more frequently in baseline samples obtained from chemosensitive rather than chemorefractory SCLC (69% vs. 17%), baseline mutations in TP53 (67% vs. 6%), ataxiateleangectasya mutated (ATM) (67% vs. 13%), and folliculin (FANC) (42% vs. 0%) are more frequent among samples obtained from chemorefractory SCLCs. This evidence concerns the gene APC and small cell lung carcinoma.