CXCL12 and neoplasm: As polarized macrophages differ in terms of receptor expression, chemokine production and effector functions [4], to observe the effect of MSC-derived CXCL12 on BMDM phenotype, we analyzed secretion of phenotype-specific cytokines, expression of a phenotype-specific CD marker, spheroid formation rate in three dimensional coculture assays and tumor initiation rate after in vivo tumor induction.