Category A - full version without watermark 1024x576 (check terms and conditions at The version with watermark is for free to embed . Description: The basis for tumor growth is angiogenesis; that is the creation of a blood supply to support the growth tumor cells with oxygen and other nutrients. The use of angiogenesis inhibitors causes blood vessel maturation and regression in tumors. By this mechanism, the growth of a tumor can be stopped or slowed in certain circumstances.