IL2 and pulmonary sarcoidosis: Figure 4 confirms that steady state level of Tregs sensitively depends on the parameter k2a (which is the coefficient of the dependence of Treg proliferation on IL-2). Figure 4B corresponds to state 8 in Table 1, wherein Tregs are elevated along with Teff and macrophages. This represents the clinical scenario wherein active pulmonary sarcoidosis is paradoxically associated with anergy to new antigens (i.e., suppression by Tregs) [4].