Galanin-2 receptor gene. Physical locations of the four genotyped single nucleotide polymorphisms (SNPs). Coding exons are shown as solid blocks. SNP locations are from the SNP Browser software and the Panther Classification System public database, February, 2006. P values for the effect on one-year SF-36 Mental Health scores of the SNP x 3–6 month pain interaction term are shown above each SNP.