PRTN3 and rheumatoid arthritis: In general, the studies included healthy individuals as a control group, except for the studies reported by Nakajima et al. [17], Ediz et al. [25], and Nzeusseu Toukap et al. [19], in which Diabetes Mellitus (DM), RA anti-ACPA (−), and Osteoarthritis (OA) were included, respectively.