Inducible gene expression in mammalian cells and transgenic mice.

Advances in biomedicine have accentuated the need to develop methods to deliberately modulate gene activity. In addition to improved versions of the system based on components of the tetracycline resistance operon, several strategies have recently emerged to control gene function at the transcriptional level. Particularly promising are approaches based on non-mammalian steroid hormones, and on small molecules that bind immunophilins.