Allostasis (/ˌɑːloʊˈsteɪsɪs/) is a physiological mechanism of regulation in which an organism anticipates and adjusts its energy use according to environmental demands. First proposed by Peter Sterling and Joseph Eyer in 1988, the concept of allostasis shifts the focus away from the body maintaining a rigid internal set-point, as in homeostasis, to the brain's ability and role to interpret environmental stress and coordinate changes in the body using neurotransmitters, hormones, and other signaling mechanisms. Allostasis is believed to be not only involved in the body's stress response and adaptation to chronic stress; it may also have a role in the regulation of the immune system as well as in the development of chronic diseases such as hypertension and diabetes.