Accordingly, it contained genes that have already been associated with SCLC progression such as Achaete-scute complex homolog 1 (ASCL1), Neural cell adhesion molecule 1 (NCAM1/CD56), Thyroid transcription factor-1 (TTF-1) and Insulinoma associated-1 (INSM1) [24,25] (Additional file 2). This evidence concerns the gene NCAM1 and small cell lung carcinoma.