Patients are then categorized based on presence or absence of one or more of the following poor prognostic features: functional limitation (e.g., HAQ score or similar valid tools); extra-articular disease (e.g., presence of rheumatoid nodules, RA vasculitis, Felty’s syndrome); RF or ACPA antibodies; bony erosions on radiographs. Here, PRTN3 is linked to rheumatoid arthritis.