In some cases, drug companies may want to avoid interfering with key proteins to avoid too many unintended side effects, says Marc Vidal, director of the Center for Cancer Systems Biology at Dana-Farber Cancer Institute in Boston.
It's a model that scientists have tried with spider silk before, but because the proteins in spider silk are so large, it takes some pretty wacky-sounding techniques to replicate them (like getting it from the milk of transgenic goats).