CDH1 and small cell lung carcinoma: In additional, we analysed CDH1 and CTNNB1 expressions from the gene expression database of SCLC cell lines (https://sclccelllines.cancer.gov/) [21] (Additional file 4: Figure S3), and found that their expressions were not related in SCLC cell lines (r = 0.01671, p = 0.443).