CCL2 and neoplasm: By enzyme-linked immunosorbent assay (ELISA), 4T1 tumor-bearing mice showed elevated CCL2 serum levels compared to healthy mice (mean±s.e.m.=393±108.4 pg/ml) (Fig. 7A), within range of those in patients with breast cancer (mean range=192-398 pg/ml) (Dwyer et al., 2007; Lubowicka et al., 2018).