AbstractSince the discovery of antibiotic therapeutics, the battles between humans and infectious diseases have never been stopped. Humans always face the appearance of a new bacterial drug‐resistant strain followed by new antibiotic development. However, as the genome sequences of infectious bacteria have been gradually determined, a completely new approach has opened. This approach can analyze the entire gene resources of bacterial drug resistance. Through analysis, it may be possible to discover the underlying mechanism of drug resistance that will appear in the future. In this review article, we will first introduce the method to analyze all the xenobiotic transporter genes by using the genomic information. Next, we will discuss the regulation of xenobiotic transporter gene expression through the two‐component signal transduction system, the principal environmental sensing and response system in bacteria. Furthermore, we will also introduce the virulence roles of xenobiotic transporters, which is an ongoing research area. © 2008 IUBMB IUBMB Life, 60(9): 569–574, 2008