S100A13 is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100 family members are localized in the cytoplasm and/or nucleus of a wide range of cells， and are involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. S100A13 is extensively expressed in various types of tissues with an elevated expression level in the thyroid gland. In smooth muscle cells， S100A13 co-expresses with other family members in the nucleus and in stress fibers， suggesting diverse functions in signal transduction.
