CCND1 and post-traumatic stress disorder: According to a systematic review of the literature, the Bcl1 single nucleotide polymorphism (SNP) within NR3C1 and four SNPs within FKBP5 (rs1360780, rs3800373, rs9296158, rs9470080) are particularly prominent HPA axis related risk factors for the development of PTSD (Carvalho et al. 2017).