Although originally described as a potent T cell growth factor in vitro, the main non redundant role of interleukin-2 (IL-2) in vivo is now known to be the maintenance of peripheral T cell tolerance. As well as promoting the proliferation and survival of recently activated effector T cells, IL-2 also plays a critical role in regulatory T cell (Treg) homeostasis and has been variously described ...

In this paper, we consider characterizations based on the Bhattacharyya matrices. We characterize, under certain constraint, dis tributions such as normal, compound poisson and gamma via the diago nality of the 2 X 2 Bhattacharyya matrix.