Hemidesmosomes are subcellular structures that are involved in the attachment of a variety of epithelial cells, including basal epidermal keratinocytes, to the extracellular matrix. Like desmosomes, they provide a link between the intracytoplasmic keratin intermediate filaments and the plasma membrane. Major hemidesmosome plaque components include the bullous pemphigoid antigens of 230 and 180 kD and the α6β4-integrin. These transmembrane proteins may associate extracellularly with anchoring filament components including the 19-DEJ-1 proteoglycan and the polymeric proteins nicein/kalinin and epiligrin. Several of these hemidesmosome-related components have been implicated as targets for circulating auto-antibodies in immunobullous disorder