PTEN and gastric cancer: Du et al. co-cultured exosome miR-23a from GC cells with human umbilical vein endothelial cells (HUVECs) and found that VEGF expression was increased, TSP-1 expression was decreased, and PTEN expression was inhibited, suggesting that GC cell-derived exosome miR-23a could promote angiogenesis [40].