TNF and breast cancer: Interestingly, LPS combined with SM-164 also significantly causes the regression of the ER+ breast cancer from MCF7 cells expressing a low level of cIAP1/2 at both early and late stages in the mouse model (Figure 7D) because LPS stimulates macrophages to produce TNFα (50, 57), which inhibits MCF7 cell proliferation directly (Figure 7C) and also cause its rapid apoptosis in combination with SM-164 (Figure 7A).