RA is a prevalent autoimmune disease characterized by synovitis and hyper-plasia (“swelling”), production of autoantibodies (rheumatoid factor and anti–citrullinated peptide antibodies [ACPA]), destruction of cartilage and bone (“deformity”), and systemic features such as cardiovascular, pulmonary, psychological, and skeletal abnormalities [33]. Here, PRTN3 is linked to autoimmune disease.