Pyruvate kinase M2 (PKM2) expression is associated with clinical metastasis and may be an important inducer of premetastatic niche formation, evidenced by the fact that PKM2 transfer from PCa exosomes to bone marrow stromal cells regulates stromal cell-derived factor 1 (SDF-1) and directs the bone marrow to contribute to premetastatic niche formation [49]. Here, CXCL12 is linked to posterior cortical atrophy.