SMN1 and oral lichen planus: Lundstrom reported 27% serum autoantibody positivity including rheumatoid factor (RF), ANA, and anti-smooth muscle autoantibody (SMA) in OLP patients.[13] Besides hypothyroidism and thyroid diseases, a possible association has been also reported between OLP and other immune-mediated disease,[20] namely ulcerative colitis and alopecia areata.[21] Systemic lupus erythematosus and rheumatoid arthritis were reported to be associated with autoimmune thyroid disease.[22]