The difference in response rate between vestibular schwannomas and meningiomas does not seem to correlate with degree of angiogenesis, since expression of VEGF in the tumor, expression of VEGFR2 in tumor blood vessels, and microvascular density are greater in meningiomas than in vestibular schwannomas.[9] However, immunohistochemical analysis of expression of the VEGF pathway components shows different patterns in schwannomas and meningiomas. This evidence concerns the gene KDR and schwannoma.