Serpin I2 is a member of the serine protease inhibitor (serpin) superfamily made up of proteins which play central roles in the regulation of a wide variety of physiological processes, including coagulation, fibrinolysis, development, malignancy and inflammation.

The gene product may have a role in a growth-control, possibly growth-suppressing pathway and, when impaired, may be involved in pancreatic carcinogenesis. The protein is a member of the plasminogen activator inhibitor-1 family, a subset of the serpin superfamily whose members act as tissue-specific tPA inhibitors. Two alternatively spliced transcript variants encoding distinct protein isoforms have been found for this gene.