CXCL12 and neoplasm: It is reported that the SDF-1/CXCR4 axis could attract CXCR4-expressing tumor-associated macrophage (TAM) and myeloid-derived suppressor cell (MDSC) accumulation in TME and suppresses T-cell immune responses (Obermajer et al., 2011; Vatner et al., 2014; Séhédic et al., 2017; Jiang et al., 2019).