L.P.- lichen planus, CIMT- carotid intima-media thickness, CRP- C reactive protein, MTHFR- methyl tetra hydro folate reductase, O.L.P- oral lichen planus, CYP- cytochrome P, AS- aortic strain, AD- aortic distensibility, ASI- aortic stiffness index, Hcy- homocysteine, HHcy- high homocysteine, cfPWV- carotid-femoral pulse wave velocity, SBP- systolic blood pressure, DBP- diastolic blood pressure. The gene discussed is MTHFR; the disease is oral lichen planus.