The McKendrick–von Foerster equation is a linear first-order partial differential equation encountered in several areas of mathematical biology – for example, demography[1] and cell proliferation modeling; it is applied when age structure is an important feature in the mathematical model.[2] It was first presented by Anderson Gray McKendrick in 1926 as a deterministic limit of lattice models applied to epidemiology,[3] and subsequently independently in 1959 by biophysics professor Heinz von Foerster for describing cell cycles.