Taken together, these results suggest that tumour cells may promote the up-regulated expression of TNF in tumour-infiltrating B cells through release of PTN in the HER2 + IBC tumour microenvironment, then TNF can mediate necroptosis in tumour-infiltrating endothelial cells, which promotes both tumour cell metastasis and M2 macrophage polarization involved cancer progression (Fig. 7m). This evidence concerns the gene ERBB2 and cancer.