These differences might have several explanations, including the sample size of cohorts used, the Bayesian statistical method being better suited than the SPSS statistical package to decide about susceptibility in small samples, the classification criteria used to select RA patients (ACR 1987 versus 2010 ACR/EULAR that discriminate or not between ACPA positive RA patients), and different ethnic and regional populations. Here, PRTN3 is linked to rheumatoid arthritis.