41. HPP is rich in protein factors that potently stimulate angiogenesis . 42. The new findings come from a field of research known as tumor angiogenesis . 43. Scientists later discovered that the tumors also contain substances that can stop angiogenesis . 44. The first generation of angiogenesis -inhibiting drugs is now undergoing clinical trials. 45. Instead, he recommended trying interferon-alpha, which can thwart angiogenesis . 46. Only a few angiogenesis inhibitors have entered human trials. 47. In animal experiments, resistance to the angiogenesis agents has been remarkably absent. 48. Remember that angiogenesis begins when blood-starved areas send out receptor signals. 49. Endostatin is the most powerful of a class of substances called angiogenesis inhibitors. 50. As for anti-angiogenesis drugs, there were about 40 reports including: