Fig. 2

Logic-based representation of the model. The network contains four nodes (X1, X2, X3, and X4). The regulatory relationships are represented by arrows (representing activation) and a t-headed line (representing inhibition). Node X1 is represented as an input of the model because it has no regulator and due to the + ve FC value in the expression table, its state is initialized by ‘1’ (see BF1). Node X2 has two regulators: X1(activator) and X4 (inhibitor). The FC values of both X1 and X4 are + ve but the FC of X2 is –ve indicating the collective effect of both regulators on X2, therefore, it is encoded by the AND gate (see BF2). Node X3 has two regulators: X2 (activator) and X4 (activator). The FC expression values of X2 and X4 are –ve and + ve respectively while the FC of X3 is + ve which indicates the independent effect of regulators on X3, therefore, it is encoded by OR gate (see BF3). Node X4 is activated by only regulator X3 and both of them have + ve FC, therefore, it is encoded as the future state of X4 is dependent on the present state of X3 (see BF4). After initializing the input node, simulation was performed to ensure that the steady-state value of a node (box over the node containing 0 or 1) matched to the FC expression value (red or blue color of the node) i.e., a node with a + ve FC (blue color) is represented by a steady-state value of 1 and node with a –ve FC (red color) is represented by 0