Stem cells in normal and leukemic hemopoiesis (Henry Stratton Lecture, 1982).

This paper deals with three themes: (1) the nature of differentiation in normal and leukemic processes, (2) stochastic and deterministic control mechanisms that affect differentiation, and (3) the nature of the events that separate self-renewing stem cells from their committed descendants. These all impinge on both myelopoietic and lymphopoietic leukemias. The view is advanced that differentiation continues in these diseases, but new programs are assembled abnormally but with normal components.