A shorter duration of PMH use (1–6 years) was associated with a decreased risk of ACPA-positive RA among current users (adjusted OR 0.3, 95 % CI 0.1–0.7), while the association was not statistically significant for the ACPA-negative subset (adjusted OR 0.4, 95 % CI 0.1–1.3). The gene discussed is PRTN3; the disease is rheumatoid arthritis.