A number of studies demonstrate that there is a period of seropositive rheumatoid arthritis (RA) development that can be termed ‘Pre-RA’ during which there are elevations of circulating autoantibodies including antibodies to citrullinated protein antigens (ACPA) and rheumatoid factor (RF) in absence of and prior to the appearance of clinically-apparent inflammatory arthritis (IA) as well as a clinical diagnosis of RA (clinical RA) that may further classifiable by established criteria (1–3). This evidence concerns the gene PRTN3 and rheumatoid arthritis.