“…It is generally thought that these disorders involve a destabilization at the hematopoietic stem cell (HSC) level leading to an oscillatory e%ux of cells into all di!erentiation pathways (Mackey, 1978(Mackey, , 1979a(Mackey, , 1996. In other dynamic hematological diseases like periodic autoimmune hemolytic anemia (BeH lair et al, 1995;Kirk et al, 1968;Mackey, 1979b;Maha!y et al, 1998;Orr et al, 1968) there is only an oscillation in one of the major blood cell types. Cyclical thrombocytopenia (CT) is a rare blood disease apparently falling into this second category.…”