FAS and lichen planus: Similar to other autoimmune dermatoses, like psoriasis and lichen planus, the previous research revealed that cell-mediated cytotoxicity and apoptotic mechanisms involving cytotoxic molecules, such as granzyme B, granulysin, and perforin, and the Fas–Fas ligand pathways form a central component of AA pathogenesis [96,97,98,99,100,101,102].