Figure 1.

Mathematical model of competition among peripheral lymphocytes. The model includes the processes of bone marrow regrowth and turnover, emigration from the bone marrow to the periphery, and cell division and death in the periphery. Growth rates of bone marrow precursors decrease as a function of their number. Peripheral net growth rates (i.e. the difference between division and death rates) for each population X₁ and X₂ are down-regulated by the presence of their own numbers and the number of cells in the competing population. The model is, in fact, the Lotka–Volterra competition model with the addition of immigration.