“Dopaminergic synapse”, “Alcoholism”, and “Cocaine addiction” are pathways involving dopaminergic signaling and are ruled by the genes Drd1 and Drd2, which also show the highest log fold-changes (1.13 and 1.31, respectively; Figure 2A, Supplementary Figure S2) and belong to the core enrichment (i.e., among the most up-regulated) of the three pathways. Here, DRD1 is linked to cocaine dependence.