Human leukocyte antigen (HLA) genes at the short arm of chromosome number 6 have been reported to have a strong linkage with rheumatoid arthritis (RA) along with PTPN22 (protein tyrosine phosphatase non-receptor type 22), PADI4 (peptidyl arginine deiminase 4), STAT4 (signal transducer and activator of transcription 4), and RUN X1 (runt-related transcription factor 1) [6]. The gene discussed is PTPN22; the disease is rheumatoid arthritis.