However, the effects of childhood trauma × BDNF Val66Met interactions on long-term HPA axis activity, such as in HCC, remain unclear, although it has been suggested that Met carriers with childhood trauma may experience reduced hippocampal volume (42–44), potentially leading to prolonged HPA activation (36) and higher allostatic load (45) over time, which may result in elevated HCC levels (46). Here, BDNF is linked to hepatocellular carcinoma.