CR1 and malaria: Microcytic RBCs due to α+thalassaemia and other causes such as iron-deficiency have been shown to have reduced rosette frequencies with P. falciparum-infected RBC, which could influence susceptibility to severe malaria.35 It remains unclear whether microcytic RBC synthesise lower amounts of CR1 than normal cells, or whether some CR1 is lost, for example, through exocytosis of membrane vesicles during normal RBC ageing,36 as well as by proteolysis as described above.