The tetratricopeptide repeat (TPR) motif is a degenerate, 34 amino acid sequence found in many proteins and acts to mediate protein-protein interactions in various pathways. At the sequence level, there can be up to sixteen tandem TPR repeats, each of which has a helix-turn-helix shape that stacks on other TPR repeats to achieve ligand binding specificity. IFIT5 (interferoninduced protein with tetratricopeptide repeats 5), also known as RI58 (retinoic acid- and interferon-inducible 58 kDa protein), is a 482 amino acid protein that contains eight TPR repeats. IFIT5 expression is induced by retinoic acid and interferon stimulation. The gene encoding IFIT5 maps to human chromosome ten, which houses over 1,200 genes and comprises nearly 4.5% of the human genome.