In vitro CC-CM experiments also confirmed that BC cells (both 4T1-luc and MDA-MB-231-luc cells) could polarize microglia cells into M2 phenotype (Figure 2F) and increase the secretions of IL6 and CCL2 by microglia cells in a time-dependent manner (Figures 2D,E). The gene discussed is IL6; the disease is breast cancer.