Tumour angiogenesis factor (TAF) and its neutralisation by a xenogeneic antiserum.

Tumour angiogenesis factor (TAF) has been extracted from a variety of animal and human tumours. Its ability to induce neovascularization in two bioassays, viz. rat air-sac and chick chorioallantoic membrane, is demonstrated. Similar extracts from normal tissues fail to induce angiogenesis. TAF extracts have been used to raise a xenogeneic antiserum, the specificity of which was investigated using classical immunological methods. Its ability to neutralize the biological activity of TAF using the two in vivo assays, was also demonstrated.