PTPN22 and rheumatoid arthritis: We have previously reported that the major RA susceptibility locus, the group of HLA–DRB1 alleles collectively referred to as the shared epitope (SE), is associated with both all-cause and CVD mortality in patients with inflammatory polyarthritis (IP) and RA, but that the second-strongest susceptibility gene, PTPN22, shows no such association (3).