BMP2 and neoplasm: Therefore, in this study, in order to simulate tumor microenvironment, the recombinant lentivirus vectors expressing small hairpin RNA against BMP-2 gene (LV-SH-BMP2) and the recombinant lentivirus vectors over-expressing BMP-2 (overexpression-LV-BMP2) were respectively transfected into Hep G2 cells, and then The Hep G2 cells transfected with LV-SH-BMP2 or overexpression-LV-BMP2 were respectively co-cultured with human umbilical vein endothelial cells (HUVECs) to observe the proliferation, migration and angiogenesis of HUVECs.