found that uptake of breast cancer-derived exosomal miR-122 by niche cells (brain astrocytes and lung fibroblasts) in PMNs inhibits recipient cell glucose consumption by decreasing the expression of GLUT1 (also known as SLC2A1) and PKM2, thereby increasing nutrient utilization for cancer cells to facilitate metastasis (57). Here, PKM is linked to breast carcinoma.