To trace the exosome communication between GC cells under more realistic conditions, we established a co-cultivation system and transfected an RFP-tagged CD63 plasmid into MKN-45 and BGC-823 cells (exo-RFP-MKN-45 and exo-RFP-BGC-823) to label the exosomes within tumour cells. This evidence concerns the gene CD63 and neoplasm.