Langer R, Brem H, Falterman K, Klein M, Folkman J
Science. 1976 Jul 2;193(4247):70-2. doi: 10.1126/science.935859.
A cartilage fraction isolated by guanidine extraction and purified by affinity chromatography inhibits tumor-induced vascular proliferation and consequently restricts tumor growth. This fraction contains several different proteins; the major one has a molecular weight of about 16,000. The fraction strongly inhibits protease activity.