A family of serine proteinase inhibitors which are similar in amino acid sequence and mechanism of inhibition, but differ in their specificity toward proteolytic enzymes. Some members of the serpin family may be substrates rather than inhibitors of SERINE ENDOPEPTIDASES.

Synonyms: 0, Serpin Protease Inhibitors, Serpin, Serpin Peptidase Inhibitors, Serpins, Protease Inhibitors, Serpin, Inhibitors, Serpin Protease, Peptidase Inhibitors, Serpin, Inhibitors, Serpin Peptidase, Serpin Superfamily, Superfamily, Serpin