In the current study, as the increased putative dopamine signaling in BDNF Val/Val genotype was associated with decreased MFG DC in the PTSD group, we speculate that the inverted U-shaped relationship between dopamine signaling and frontal function may shift to the right limb in these bereaved PTSD adults (Supplementary Fig. S2). The gene discussed is BDNF; the disease is post-traumatic stress disorder.