Before revision:  The bistable switch responds to fluctuations in extracellular TMG/lactose concentration  in an asymmetric manner because of the displacement of its bistability region to the right: As noise intensity increases, uninduction becomes easier and induction becomes more difficult . The steady-state displacement due to weak and rapid extrinsic noise passing through a nonlinear filter is a universal phenomenon: It is independent of the kinetics of the system but it only depends on the filtering function. The calculation method presented enables even qualitative predictions of this effect, only by inspection of the experimental data .
After revision:  The bistable switch responds to fluctuations in extracellular TMG/lactose concentration in an asymmetric manner because of the displacement of its bistability region to the right: As noise intensity increases, uninduction becomes easier and induction becomes more difficult .