LGMN and breast cancer: On the one hand, stabilized pro-AEP can maintain a stable concentration of AEP in BC cells, thus playing a role in BC proliferation; on the other hand, in the TME, the secreted pro-AEP was activated to form AEP after a multi-step activation, thus playing its role in extracellular matrix remodeling and the mediation of tumor metastasis (Figure 2B).