Schematic depiction of the model.

Solid arrow indicates conversion of the same variable from one state to another, dotted arrow indicates influence of a variable on the transition rate, and double arrow indicates secretion of biomarkers. See expressions terms of the Model System 1–6 to understand the appropriateness of arrows. The initial conditions used to solve the ODE system are H* = H_max, A* = A_norm, Z* = 0, S* = S_min, L* = L_min, D* = D_min.