In a search for potential DNA methylation biomarkers of postpartum depression using MWAS and a parallel study in mice, Guintivano and colleagues found that DNA methylation at the heterochromatin protein 1 binding protein 3 (HP1BP3), and tetratricopeptide repeat domain 9B (TTC9B) genes predicted postpartum depression in the original and replication cohorts [267]. Here, TTC9B is linked to postpartum depression.