REEP4 and myelodysplastic syndrome: The four genes are located on different chromosomes (REEP1 is at 2p11.2, REEP2 lies within the myelodysplastic syndrome (MDS) 5q31.2 microdeletion [35], REEP3 is at 10q21.3 and REEP4 at 8p21.3), and the genes for human REEPs 1–4 are in chromosomal segments that share conserved neighbouring genes: that is, they reside in ‘paralogons’ (figure 4).