PRTN3 and rheumatoid arthritis: This could be a result of markers used for the identification of infiltrating cells, cohort size or assay of choice, however, the overall consensus has hinted at chemokine and proinflammatory cytokine differences between ACPA− and APCA+ RA, but there has been limited investigation of the potential for differential proinflammatory cytokine T cell responses and polyfunctionality [11,13,14].