VEGFA and neoplasm: Therefore, HIF-1α/VEGF/VEGFR pathway was a key signal pathway to regulate tumor angiogenesis.25 In this study, immunohistochemical results showed that the expressions of HIF-1α, VEGF and VEGFR-2 in the D+M+U group were significantly decreased (P < 0.01), indicating that ultrasound combined with schisandrine A microbubbles could effectively inhibit the HIF-1α/VEGF/VEGFR pathway, thereby acting as an anti-tumor agent.