To our knowledge, to date, the region of interest on chromosome 13q21.1 has not been reported as a major locus in the few GWAS of mood disorders.10, 12, 13, 14, 15 Those negative results may reflect the fact that the sample size of individual GWAS is still small, as our meta-analysis combining the GWAS and independent replication samples was necessary to detect associations of PCDH17 SNPs. The gene discussed is PCDH17; the disease is mood disorder.