Mathematical Modelling of the Inhibitory Role of Regulatory T Cells in Tumor Immune Response

Figure 5

(a) Stability region of and Hopf bifurcation curve in parameter plane. is stable in region I and unstable in region II. (b) ACI curve. is stable in region III and unstable in region IV. (c) The bifurcation diagram of with respect to for fixed . Hopf bifurcation point appears at . (d) The bifurcation diagram of with respect to for different (the blue curves represent the stable steady states of system (34), while the red curves represent the unstable steady states).

(a)

(b)

(c)

(d)