Importantly, addition of a TNFα receptor/IgG:Fc fusion protein (TNFR:Fc)38,39 blocked apoptosis induced by IL-4-polarized macrophages and SM-164 (Fig. 4C), suggesting that IL-4-polarized WT macrophages produce TNFα to trigger SM-164 induction of BC apoptosis. Here, TNFRSF1A is linked to breast cancer.