Both upregulation of angiogenic stimulators and downregulation of angiogenesis inhibitors result in tumor blood vessel proliferation, which is the bases of the tumor growth and metastasis.

• 征募宿主细胞，如巨噬细胞、淋巴细胞、纤维细胞，使它们分泌促血管生长因子。各类促血管生长因子过量表达和血管生成抑制因子下调是导致肿瘤血管增生，引起肿瘤生长和转移的基础。