Molecular studies have identified several associated mutations in neuroendocrine carcinoma (PIK3CA, MYC, TP53, PTEN, ARID1A, KRAS, BRCA2) and gastric-type adenocarcinoma (KRAS, ARID1A, PTEN) that may serve as molecular targets. Here, KRAS is linked to neuroendocrine carcinoma.