Zheng and colleagues have noted that exosomal miR-21 that is directly transferred from tumor-associated macrophages to the GC cells may confer cisplatin-resistance in GC by suppressing cell apoptosis and activating the PI3K/AKT signaling pathway, which in turn is achieved by downregulation of PTEN expression [96,97]. This evidence concerns the gene AKT1 and neoplasm.