The migration of macrophages to these hypoxic regions is driven by soluble factors secreted by the tumor into the circulation, including VEGF, endothelial monocyte-activating polypeptide II (EMAPII), endothelin-2, C-X-C chemokine receptor 4 (CXCR4), and semaphorin3A 40. Here, AIMP1 is linked to neoplasm.