Although CXCR4 expression has been previously correlated with human PDAC, we show here that human PDAC malignancy is halted following re-expression of its cognate ligand CXCL12.Specifically, CXCL12 interrupted both primary tumor growth, through cell-cycle arrest, and cancer cell metastasis, leading to increased overall survival in diseased animals. Here, CXCR4 is linked to cancer.