The mechanism of action by which TMPD induces arthritis consists of neutrophil and mononuclear cell infiltration into the joint cavity, as well as the development of synovial hyperplasia by pannus formation, at the same time there is a raise of mRNA relative to the increase of the protein expression of cytokines like TNF-α, IL-1β and IL-6, the increase of seric levels of rheumatoid factor and autoantibodies against type I and II collagen and complemented by the augmentation of the articular joints [15,16]. This evidence concerns the gene TNF and Arthritis.