MAPK3 and neoplasm: Some studies evidence that CXCR7 activates PI3K and MAPK signaling controlling cell growth and survival in normal and tumor cells;14, 15, 17, 18, 35, 36 our previous observations showed that the expression of CXCR4 and CXCR7 predicted shorter disease-free survival in renal cancer patients.10 In this manuscript, CXCL12 activates CXCR4/CXCR7 signaling through p38 and ERK1/2 MAPK.