NGB and colorectal carcinoma: Immunohistochemistry (IHC) staining showed that NGB protein levels were lower in colon tumor tissues than in normal colon tissues (Fig. 1B); Human Protein Atlas (HPA) database also showed similar tendency, with almost half exhibiting weak/negative expression in total 11 CRC tissues (45.5%), and nearly all showing moderate expression in normal colon (Additional file 1: Fig. S2, image available from version 22.0.proteinatlas.org) [22, 23].