Glutamate-rich protein 3, also known as Uncharacterized Protein C1orf173, is a protein encoded by the ERICH3 gene. ERICH3 was named “chromosome 1 open reading frame 173 (C1orf173)” based on its map location in the human genome. It was subsequently renamed “E-rich 3” as a result of the high content of glutamate (E) in its encoded amino acid sequence. Single-nucleotide polymorphisms (SNPs) in the ERICH3 gene has been identified as one of the "top" signals in a genome-wide association study (GWAS) for plasma serotonin concentrations which were themselves associated with selective serotonin reuptake inhibitor (SSRI) response in major depressive disorder (MDD) patients. The same ERICH3 SNP was later demonstrated that was significantly associated with SSRI treatment outcomes in three independent