ADCYAP1R1 and post-traumatic stress disorder: Other stress-related candidate genes include SKA2 and ADCYAP1R1; a study showed associations between the methylation status, a polymorphic site in the 3′UTR of the SKA2 gene—involved in mitosis—with reduced thickness of several cortical areas and symptom severity in PTSD (Daskalakis and Yehuda, 2014).