Angiogenesis assays: problems and pitfalls.

Many studies of angiogenesis inducers and inhibitors rely on in vitro or in vivo models as indicators of efficacy. However, as valuable as these models are, there are limitations to each one of these. This overview describes some of the principal methods now in use and discusses the advantages and some of the limitations of these methods. It is suggested that multiple assays, involving both in vitro and in vivo assays, are at present the best way to minimize the problems inherent in any specific assay.