PTPN22 and Autoimmunity: For this purpose, we analyzed two well-known CSK (CSK rs34933034 and CSK rs1378942) and two functional PTPN22 (PTPN22 rs2476601 (R620W) and PTPN22 rs33996649 (R263Q)) polymorphisms, previously associated with autoimmunity, in the largest series of Caucasian patients with this vasculitis ever assessed for genetic studies.