PTPN22 and rheumatoid arthritis: Genetic variation in the promoter region of FCRL3 i.e. FCRL3 -169T>C allele is reportedly associated with other autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus, [43, 47, 48] suggesting that the FCRL3 locus may influence the susceptibility to multiple autoimmune diseases in a similar manner to the immune regulating CTLA4, PTPN22 and MHC genes [24, 25, 32].