MRC1 and breast cancer: After co-culturing human breast cancer cell lines (MDA-MB-231, MDA-MB-468, and MCF-7) with PMA-induced human monocyte THP-1 cells for 48 h, we found that either STAT3 knockdown or JAG1 knockdown in breast cancer cells reduced the relative mRNA levels of CD206 and CD163 in THP-1 derived macrophages (Fig. 4a).