Modulates P53/TP53 protein levels, and thereby plays a role in the regulation of cell survival and apoptosis. Depending on the context, it can promote cell proliferation or apoptosis. Plays a role in the regulation of cell migration by modulating the levels of MMP2, a matrix protease that is under transcriptional control of P53/TP53. Does not bind calcium. Homodimer. Interacts with AGER. Expressed at highest levels in colon and at moderate levels in thymus, kidney, liver, small intestine, and lung. Low expression in heart and no expression is seen in brain, skeletal muscle, spleen, placenta and peripheral blood leukocytes. Belongs to the S-100 family. Part of the residues that are essential for calcium binding are not conserved, resulting in loss of calcium binding at physiological calcium concentrations.