The intracellular serpin family.

The serpins are widely distributed, structurally related family of proteins with diverse functions. Most of the known serpins are proteinase inhibitors, the majority being found as secreted species, however, there are a few that occur intracellularly and their physiological role remains unknown. Most of the intracellularly occurring serpins have been classified into the ovalbumin subfamily. The possible phytogenetic tree of 14 intracellular serpins is presented.