Mutations affecting this region may indeed result in inhibition of different classes of proteinases, as shown for SCCA1 and SCCA2 (Kato, 1996) or in a loss or change of function, as described in several human diseases affecting different members of the ovalbumin family of serpins, including emphysema and cirrhosis, haemorragic diseases, thrombosis and familial angioedema (Carrell and Lomas, 2002). This evidence concerns the gene SERPINB3 and Venous thrombosis.