Newer versions of traditional approaches... This article reviews traditional approaches and illustrates their inherent limitations. But that does not necessarily make the companies that create them bad investments. Often time-to-market is faster and these drugs address large markets. In general the risk is less because actions and toxicity are to some extent predictable, and even a small improvement can result in quick FDA approval. These are the known quantities. Do not expect a cure for cancer here, but do not underestimate the potential to make a lot of money. Largely because of that, companies continue to develop new versions of the tried and true methods.