CXCL12 and cancer: The two receptors of CXCL12, CXC receptor 4 (CXCR4) and atypical chemokine receptor 3 (AKRC3, also known as CXCR7), are expressed on PDAC cells, and an elevated expression of CXCR4 is associated with a poor prognosis in several cancer types [12].