MRC1 and breast cancer: To explore if the expression of CD206 in macrophages is dependent on stimulatory factors from tumor cells (tumor educated macrophages),39 conditioned media was collected from an established cell line (E18-14C-27 cells) derived from a mammary tumor of an MMTV-Neu mouse.24 When RAW 264.7 (macrophage-like) cells were stimulated with conditioned media from the E18-14C-27 cancer cells and treated with increasing concentrations of LG268 for 24 h, a decrease in the expression of CD206 was observed by immunoblotting (Fig. 2e).