PKP1 and neoplasm: However, the functional study of gain or loss and immunohistochemistry identification of desmosomal components have revealed contradictory roles for some desmosome members, including DSG2 [65,73,74,75], DSG3 [26,65,66,76], PKP1 [27,77,78], and PG [70,79,83] in HNC, suggesting that the role of the desmosomal components in HNC may be affected by some other signal transduction molecules or/and modifications related to the tumor microenvironment.