These genes include CFAP45, PCDH9, LAMC3, FAM19A5, PRKG1, PLEKHG5, TCERG1, and MTRR. For example, an epigenome-wide DNA methylation study in soldiers found an association between post-traumatic stress disorder and the DNA methylation of the CFAP45 gene [45]. Here, PCDH9 is linked to post-traumatic stress disorder.