The inclusion of subtype-specific markers (ASCL1, NEUROD1, POU2F3, and maybe YAP1) for immunohistochemistry staining besides neuroendocrine markers, such as SYP and NCAM1, will benefit the physicians in diagnosing patients with specific SCLC subtypes and predicting the potential treatment response. This evidence concerns the gene NCAM1 and small cell lung carcinoma.