CXCL12 and non-small cell lung carcinoma: As a whole, it is important to recognize that sufficient evidence exists to support a pro-tumorigenic role for CXCL12/CXCR4 in NSCLC (acting locally to support tumor growth, to enhance angiogenesis, to promote chemo-resistance and to generate an immune permissive state as well as acting distally to promote metastasis formation).