and implicated in problematic opioid use;38 phosphodiesterase 4B (PDE4B: rs7528604, p=5.68E-10, chr. 1), which has regulatory effects on dopaminergic pathways and has been implicated in GWAS of externalizing behaviors,39 smoking initiation,37,39 and general liability for addiction;36 and neural cell adhesion molecule 1, NCAM1 (rs9919558, p=4.44E-12, chr. 11), which modulates dopamine signaling41 40 and has been associated with several smoking-related traits.35,37 We also identified an association with a deleterious (CADD=18.9)42 SNP (rs986391, p=3.08E-14, chr. 5) in the TENM2 gene, recently implicated in smoking initiation, cigarettes per day, and smoking cessation.13
