Table 3 The key genetic factors and biological mechanisms in the breast cancer brain metastasis

Anti-cancer immunity

The absence of microglia can promote metastasis and diminish the responses provided by natural killer cells and T cells

Increase in the anti-tumor immunity by microglia

Reduction in breast cancer brain metastasis

[94]

[69]

[68]

[66]

[67]

PVR/CD155

Brain metastasis-associated fibroblasts are capable of secreting fucosylated PVR/CD155

The secretion of PVR is a result of HIF-1α

[95]

Lipocalin-2

The presence of interactions among innate immune cells and astrocytes can elevate neuroinflammation and brain metastasis through lipocalin-2

[96]

[64]