S100Z belongs to the S100 calcium-binding family []. The function of S100Z is unclear. S100 proteins exhibit unique patterns of tissue- and cell type-specific expression and have been implicated in the Ca2+-dependent regulation of diverse physiological processes, including cell cycle regulation, differentiation, growth, and metabolic control. S100Z is normally expressed in various tissues, with its highest level of expression being in spleen and leukocytes []. Preliminary structural data suggests that S100Z is homodimer, however a heterodimer with S100P has been reported. S100Z is capable of binding calcium ions. When calcium binds to S110Z, the protein experiences a conformational change, which exposes hydrophobic surfaces on the protein. In comparison with their normal tissue counterparts, S100Z gene expression appears to be deregulated in some tumour tissues [, ].
