Desmoglein 3 (DSG3) is a
calcium-binding transmembrane glycoprotein component of desmosomes in vertebrate
epithelial cells. Desmosomes are cell-cell junctions between epithelial,
myocardial, and certain other cell types. Currently, three desmoglein subfamily
members have been identified and all are members of the cadherin cell adhesion
molecule superfamily. These desmoglein gene family members are located in a
cluster on chromosome 18. This protein has been identified as the auto antigen
of the autoimmune skin blistering disease pemphigus vulgaris. Lung studies have
shown that DSG3 had a sensitivity and specificity of 83% and 100% respectively,
in detecting squamous cell carcinoma (SqCC) versus adenocarcinoma. Thus, DSG3 is
a first class marker for lung SqCC and can be a useful ancillary marker to
separate SqCC from other subtypes of lung cancer. Other studies have shown that
DSG3 expression in Lung SqCC indicated a poor prognosis in lung cancers and
portends a more aggressive clinical
outcome.