“Genetic biomarkers included neurotransmitter pathways associated with brain reward processes for dopaminergic (e.g., DRD2, MAOA, … (e.g., HTR3A, HTR1B, HTR3B, and SLC6A4), GABAergic (e.g., GABRA1, GABRA2, and GABRG1), glutaminergic (GAD1, GRIK3, and GRIN2C) and opioid (e.g., OPRM1, … OPRK1) pathways which presumably impact reinforcing properties of alcohol.”