We established a specific antibody against ACTN4-SpEx8 and observed protein expression in SCLC and large cell neuroendocrine carcinoma (LCNEC) with immunohistochemistry among pathological samples of adenocarcinoma, squamous cell carcinoma, LCNEC, carcinoid, and SCLC. This evidence concerns the gene ACTN4 and small cell lung carcinoma.