Caberlin, MartinMackey, MichaelNigam, Nilima2007-08-162007-08-162002-09https://hdl.handle.net/11299/3823We present some recent results concerning stiffness in the Satillán-Mackey model of the tryptophan operon. In particular, we describe the existence of invariant manifolds in this system, and describe their biological significance.