NR3C1 and post-traumatic stress disorder: Methylation analysis was performed on salivary samples of each student collected via Oragene kits (DNA Genotek); 89 CpG sites within the NR3C1 gene and 52 CpG sites within the FKBP5 gene were investigated for the association with the three different possible responses to trauma (PTG, PTSD, resilience).