NNMT and gastric cancer: NNMT overexpression was also detected in exosomes isolated from GC patients with peritoneal metastasis (PM) compared with those without PM, as well as in exosomal vesicles obtained from GC cell line (GC-114, GC-026, MKN45, and SNU-16) with respect to GES-1 normal human gastric epithelial cells.