S100A11 is a 10-12kD member of the S100 family, EF-hand superfamily of Ca-binding proteins. It is produced by smooth muscle and keratinocytes. Intracellularly, it suppresses growth; extracellularly, it exists as both a monomer, homodimer, and heterodimer with S100B, binds to RAGE, induces EGF, and promotes cell growth. Human S100A11 is 105aa in length. It contains two EF-hand motifs aa13-49, 55-90 and one high-affinity Ca- binding site aa68-79, and binds annexin I with its C-terminal half. There may be one alternative splice form that apparently contains a series of mutations over aa61-79 and shows 90aa identity to the standard form. Full-length human S100A11 shares 78-82aa identity with mouse and porcine S100A11, respectively.