Several systems are now available that enable transcription of a gene
introduced into mammalian cells to be controlled using small molecules
. Among the potential applications are the analysis of gene function t
hrough creation of inducible alleles in cell culture and transgenic an
imals, and, ultimately, the pharmacological control of therapeutic pro
tein production in vivo in the context of gene therapy. Highlights of
the past year include several demonstrations of regulated protein prod
uction in animal models of gene and cell therapy, and the development
of a new approach to transcriptional regulation using chemical inducer
s of dimerization. (C) Current Biology Ltd ISSN 1367-5931.