The comparison between the patient groups with a similar disease activity revealed that patients with RA and moderate and high disease activities (DAS-28 = 3.2–5.1 and >5.1, respectively) were significantly different from S-IA patients with similar DAS-28 scores, as far as the disease duration, ACPA positivity and number of joints with erosions were concerned (Table 4). Here, PRTN3 is linked to rheumatoid arthritis.