We have observed a significant increase in frequency of EMRA CD4 T cells and regulatory T cells in ACPA+ve patients with arthralgia irrespective of whether they developed RA or not, p = 0.041 and p = 0.032 respectively compared to ACPA−ve arthralgia patients [Fig. 5b; Fig. 5c]. Here, PRTN3 is linked to rheumatoid arthritis.