According to an epidemiological investigation in a Swedish cohort, having more than one pregnancy amplified the risk of anti-citrullinated-protein antibody (ACPA)-negative RA in females of reproductive age.6Nevertheless, Guthrie et al.7studied 310 RA patients and 1,418 controls and found that parous women were around 40% less likely to receive the RA diagnosis.6, 7Another study, by Peschken et al.,8also showed that greater parity reduced the chances of being diagnosed with RA. The gene discussed is PRTN3; the disease is rheumatoid arthritis.