Adipokine that modulates insulin action by specifically inhibiting its target protease KLK7 in white adipose tissues. Inhibition of KLK7 is enhanced by heparin. Highly thermostable, with a Tm value of 70 degrees Celsius. Incubation at 60 degrees Celsius for two hours has no apparent effect on KLK7 inhibition activity. Polymerization is observed at 70 degrees Celsius and above. Forms a stable complex with KLK7. Expressed in visceral adipose tissues. The reactive center loop (RCL) extends out from the body of the protein and directs binding to the target protease. The protease cleaves the serpin at the reactive site within the RCL, establishing a covalent linkage between the carboxyl group of the serpin reactive site and the serine hydroxyl of the protease. The resulting inactive serpin-protease complex is highly stable. Glycosylation slightly decreases affinity for heparin, but otherwise has no significant effect on KLK7 inhibitory activity or thermal stability of the protein. Belongs to the serpin family.