Except for ‘Rhupus’ [which is by some considered an overlap syndrome between rheumatoid arthritis (RA) and SLE, while by others a distinct erosive subset of SLE arthropathy with a strong association with anti-citrullinated protein antibodies (ACPA) antibodies], joint involvement in SLE is traditionally regarded as nonerosive [32, 33]. Here, PRTN3 is linked to rheumatoid arthritis.