The expression of specific target genes, such as transcriptional regulators belonging to the LuxIR family of proteins, is coordinated by synthesis of diffusible acylhomoserine lactone (AHL) molecules. C4-HSL is a small diffusible signaling molecule involved in quorum sensing, controlling gene expression, and cellular metabolism.{13434} The diverse applications of this molecule include regulation of virulence in general, infection prevention, and formation of biofilms.{13433,14086,14087,14088,14089,14093}