Paddock et al. implemented an association study based on the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) cohort and found that rs1954787 in the GRIK4 gene, which encodes the kainic acid-type glutamate receptor KA1, was associated with response to the antidepressant citalopram [39]. The gene discussed is GRIK4; the disease is major depressive disorder.