SerpinA12, also known as OL-64 and Vaspin, a newly identified adipokine, is a member of serine protease inhibitor family. SerpinA12 is also a unique insulin sensitizing adipocytokine in obesity. A recent publication indicates that induction of human vaspin mRNA expression in adipose tissue is regulated in a fat depot-specific manner and could be associated with parameters of obesity, insulin resistance, and glucose metabolism.