Merkel cells express desmosomal proteins and cytokeratins.

Indirect immunofluorescence experiments performed on various mammalian tissues rich in Merkel cells show that these cells contain keratin intermediate filaments and desmosomal proteins, which demonstrates their epithelial nature. Although they share desmosomes with neighbouring keratinocytes, Merkel cells differ from them, since they contain keratin polypeptides usually found in simple epithelia. In that respect, Merkel cells resemble fetal keratinocytes.