Thus, in Irp1-/- mice, Irp1 deficiency derepresses HIF2α translation, which transcriptionally increases EPO expression and subsequently drives red blood production, leading to polycythemia as a consequence (Anderson et al., 2013; Ghosh et al., 2013; Wilkinson and Pantopoulos, 2013). The gene discussed is EPO; the disease is polycythemia.