Adding nicotine to the mineral water of experimental RA model mice four days before induction of the disease significantly reduces the amount of TNF-α and reduces the symptoms of the disease.57 In 2019, Golbahari and Abtahi Froushani showed that treatment with nicotine could reduce some of the hematological and biochemical parameters of rats with rheumatoid arthritis, like C-Reactive Protein, Rheumatoid factor, Myeloperoxidase, Nitric oxide, TNF-α, IFN-, γ IL-17, IL-6, and IL-1.58 This evidence concerns the gene MPO and rheumatoid arthritis.