There were 13 genes enriched in cocaine addiction and the circadian entrainment signaling pathway (Bdnf, Gnai1, Gnai3, Grin2d, Grm2, Maob, Cam2, Camk2g, Gng12, Mapk1, Pcb4, Prkm2, and Pdyn). The gene discussed is GRM2; the disease is cocaine dependence.