MSR protein sequences of selected mammals (human, ENST00000264668; chimp, ENSPTRP00000028690; macaque, ENSMMUP00000024676; bushbaby, ENSOGAP00000000920; treeshrew, ENSTBEP00000011472; cat, ENSFCAP00000014011; dog, ENSCAFP00000014869; cow, ENSBTAP00000012372; mouse, ENSMUSP00000039810; rat, ENSRNOP00000024041; opossum, ENSMODP00000002568; guinea pig, ENSCPOP00000005952; hedgehog, ENSEEUP00000001324; squirrel, ENSSTOP00000004416; and rabbit, ENSOCUP00000003139) were aligned using Clustalw [33] and visualized using GeneDoc [34]. For clarity, only the first 100 amino acids are shown.