IREB2 and polycythemia: It has been reported that a syndrome of progressive neurodegenerative disease and anemia develops with iron deposits in white matter and a loss of Purkinje cells in IRP2-/- mice, whereas IRP1-/- mice develop polycythemia and pulmonary hypertension, indicating a prominent role of IRP2 in controlling neuronal iron metabolism (Meyron-Holtz et al., 2004; Wilkinson and Pantopoulos, 2014).