BDNF and breast cancer: Furthermore, XYKAJY formulation was found to reduce hyperfunction of HPA axis and the content of breast cancer marker in the blood, promote the content of monoamine neurotransmitter, and protect the pathological changes of the hippocampus and tumor, as well as upregulating the expression of GR, CREB, and BDNF in the hippocampus and decreasing NR2A, NR2B, CaMKII.