For example, PDCD1 has been shown to be associated with lupus nephritis and anti-phospholipid antibodies in ethnic subgroups [4], and PTPN22 is primarily associated with anti-cyclic citrullinated peptide (anti-CCP) [22] and rheumatoid factor (RF) [23] autoantibody positive RA. The gene discussed is PTPN22; the disease is rheumatoid arthritis.