Zhang et al. (2010) showed that the elevated expression of CCL2 positively correlates with the increased tumor-associated macrophages numbers in several human tumors. CCL2-treated neural stem cells showed a significantly increased capacity for self-renewal, proliferation, and neuronal differentiation (Hong et al., 2015). Loss of CCL2 significantly inhibited tumorigenesis (Tsuyada et al., 2012). Here, CCL2 is linked to neoplasm.