(a) Metabolic network with positive feedforward and negative feedback. All enzymatic reactions are assumed to follow Michaelis-Menten or Hill kinetics except for those corresponding to v2 and v5, which are assumed to be represented with an Irreversible General Hyperbolic Modifier Kinetic function and with an Irreversible Hill function with one modifier, respectively (see Eq. (14) for details). (b) Sets of initial conditions used to generate six different datasets. (c) Time series data corresponding to the first set of initial values in (b); X1, X2, X3, X4 are represented by blue, red, orange, and green dots, respectively.