The major acute phase serum protein in pigs is homologous to human plasma kallikrein sensitive PK-120.

A major acute phase protein (pig-MAP) has been isolated from the sera of pigs after turpentine injection. The protein is the pig counterpart of a recently cloned human serum protein denominated PK-120, which is a putative substrate for kallikrein [Nishimura et al., 1995 FEBS Lett. 357, 207-211]. The protein exists in other mammalian species and it is also an acute phase protein, at least in the rat. Pig-MAP shows homology, as PK-120, with the heavy chain 2 (HC-2) of the inter-alpha-trypsin inhibitor superfamily but does not possess trypsin inhibitory activity.