ERVW-1 and lichen planus: For this, we used monoclonal antibody 1F11B10, shown to recognize the surface-associated (SU) subunit of Syncytin-1, and immunohistochemistry (IHC) of an extended series of formalin-fixed, paraffin-embedded (FFPE)-skin biopsies, including also five samples of lichen ruber planus, an inflammatory dermatosis with abundant infiltrate of T lymphocytes.