The SNP associated with opioid overdose, rs12777585, is in an intron of the heat shock protein family A member 12A (HSPA12A), wherein SNPs in this region have been previously associated with externalizing behaviours (namely attention deficit hyperactivity disorder, substance use, and antisocial behaviours), educational attainment and smoking initiation59,61–63. The gene discussed is HSPA12A; the disease is overdose.