Quorum sensing has been engineered using synthetic biological circuits in different systems. Examples include rewiring the AHL components to toxic genes to control population size in bacteria; and constructing an auxin-based system to control population density in mammalian cells. Synthetic quorum sensing circuits have been proposed to enable applications like controlling biofilms or enabling drug delivery. Quorum sensing based genetic circuits have been used to convert AI-2 signals to AI-1 and then subsequently use the AI-1 signal to alter bacterial growth rate, thereby changing the composition of a consortium.