In AAs, the interaction between child adversity and all 4 FKBP5 SNPs were associated with PTSD. SNP rs9470080 had strongest conditional effect; for AAs without child adversity, those homozygous for T allele had lowest risk of PTSD, while homogygotes with adversity had highest risk. Here, FKBP5 is linked to post-traumatic stress disorder.