One of our significant loci mapped to four potentially interesting target genes; the other locus did not map to a distinct gene. Among these four, DEFB131 has been found to induce cytokine and chemokine upregulation during infection and promotes an innate immune response. There are studies suggesting that progressive changes in innate immune gene expression could facilitate the development of addiction(Crews and Vetreno, 2011). Our results provide limited but intriguing evidence of a possible link between OUD and the immune system.
