SEPTIN4 and post-traumatic stress disorder: Finally, recent work examining gene expression among responders with PTSD first identified (n = 324) differential expression of two genes (NDUFA1, CCDC85B) previously found to be dysregulated in neurodegenerative disorders [158] and, when interrogating gene expression in cell subpopulations among responders (n = 39) with/without PTSD, also identified PI4KAP1, REST, and SEPT4 genes in monocyte populations that have been previously implicated in neuronal loss and neurogenesis [159].