VEGFA and neoplasm: In vivo experiments consisted of the injection of mice with SGC-7901 cells transfected with lentivirus particles for the overexpression (OE) or knockdown (KD) of miR-155, and the results show that the miR-155 levels in serum exosomes and tumor tissues were increased in the miR-155 OE mice and downregulated in miR-155 KD mice, and were correlated with decreased levels of c-MYC and enhanced levels of VEGF mRNAs in OE mice.