CYP1A1 and multiple sclerosis: However, in agreement with the findings in multiple sclerosis (Rothhammer et al., 2016), we detected significantly reduced CYP1A1 expression in psoriasis lesional skin compared with that in nonlesional psoriasis and healthy skin, suggestive of an overall dysregulation of the AHR pathway in psoriasis where its anti-inflammatory effect may be impaired.