State-space analysis of the Teff-Treg loop. The state-space analysis was done with the simplified T-cell population model (eq. 2). The X axis represents the activated Treg population and the Y axis activated Teff cells. A)By plotting both populations with different levels of αR the equilibrium point moves to higher numbers of Teff cells, remaining practically the number of Treg cells in the same point.B)State-space plot corresponding to the two extreme values for αR: 0.21 and 2.0, showing an abrupt change in the dynamics.