CXCR4 and osteosarcoma: While the CXCL12/CXCR4 signaling stimulates Akt phosphorylation, the use of the Akt inhibitor AKTi-1/2 decreased CXCL12 and CXCR4 mRNA levels in human 143B and murine MOTO osteosarcoma cell lines [254].