PROX1 and breast cancer: Moreover, exosomes secreted by BC cells are internalized by human lymphatic endothelial cells, which triggers the upregulation of Prox1-expressing exosomes through hnRNPA2B1 recruitment and increases H3K4 trimethylation of the Prox1 promoter, leading to lymphangiogenesis and lymph node metastasis in BC cells [176].