 The total cohort of T cells in an organism maintain homeostasis – a consistent total number of T cells in the peripheral blood.Transient elevations in peripheral blood T cell counts cause the whole population to diminish, transient depletions cause the whole population to proliferate, generally maintaining a roughly total T cell count.The latter situation –lymphodepletion– has been studied extensively and the proliferation of mature T cells upon transfer into the lymphopenic host is referred to as “lymphodepletion-induced” or “homeostatic” proliferation.