In order to elucidate the tumor-promoting role of COX-2 in breast TAMs, TAMs were first transfected with adenoviral COX-2 or siRNA COX-2 (Supplementary Figure S2), and then co-cultured with different breast cancer cell lines (MCF-7 and MDA-MB-231) for 7 days. Here, PTGS2 is linked to neoplasm.