In the tumor microenvironment, PKM2 promotes tumor cells to release cytokines and aggregates a large number of MDSCs around tumor cells, PKM2 facilitates the binding of cytokines, such as CXCL1 and MIF, released by tumor cells to the surface receptors CXCR2 or CXCR4 on MDSCs. The gene discussed is CXCR4; the disease is neoplasm.