CD44 and gastric cancer: In accordance with the previous study, western blotting identified that CD44 protein levels were remarkably increased in LNM-GC cells and their sEV, especially highly expressed in HGC-27L and HGC-27L-sEV but were hardly detectable in AGS and AGS-sEV (Additional file 7: Fig. S3A, B, Additional file 6: S2G, H).