ACPA positivity in the absence of RA is a rare phenomenon; however, in ACPA‐positive healthy individuals, the presence of ACPA was not associated with HLA‐SE alleles, indicating that the HLA‐SE alleles are not associated with ACPA as such, but rather with ACPA‐positive disease.55, 56 In contrast to HLA‐SE, other alleles of HLA‐DRB1 (namely, HLA‐DRB1*13) were shown to be protective for RA development. Here, PRTN3 is linked to rheumatoid arthritis.