The study of serpin deficiency is currently one of the most active areas in basic medical research. Recently, three hypotheses concerning serpin deficiency have been proposed, which are referred to as the conformational disturbance hypothesis (CDH) , loop-sheet polymerisation hypothesis (LSPH) and multiple binding site hypothesis (MB-SH) . CDH was put forward to explicit serpin deficiency due to conformational change of reactive loop of serpins as a result of mutations occurring away from the reactive site residues and LSPH was to explain deficient serpins due to the formation of polymers. MBSH was proposed to explain the mechanism of the formation of stable enzyme-serpin complex via more than one binding site and blockage or mutation in any of the sites resulting in serpin deficiency. A combination of these mechanisms may be critical in understanding the roles of the many documented mutations and autoimmunities which result in qualitative and quantitative serpin deficiency.