PON2 and systemic lupus erythematosus: Given that PON1-2-3 gene cluster resides close to a linkage peak for SLE and our previous observations suggesting a relationship between SLE and PON activity/PON1-3 genetic variation, the purpose of this study was to investigate the remaining member of the PON multigene family, PON2. We genotyped and analyzed 19 highly informative PON2 SNPs selected from HapMap and SeattleSNPs databases in a Caucasian SLE case-control sample.