Due to the key importance of TNF-α in “organizing” the inflammatory immune response in patients, resulting, among others, from stimulating the release of matrix catabolic factors, including MMPs, cathepsins, or ROS, therapies that neutralize the action of this factor are highly effective in the treatment of chronic inflammatory and autoimmune pathologies, including JIA [35]. This evidence concerns the gene CTSS and juvenile idiopathic arthritis.