TNF and breast cancer: TNF-α, a type II transmembrane protein of the TNF/TNFR superfamily, exerts its biological effects both as a membrane-bound and soluble molecule by interacting with two receptors: TNFR1 (TNFRSF1A), broadly expressed on many cell types, including epithelial tumor cells, and TNFR2 (TNFRSF1B), predominantly found on hematopoietic cells and in BC tissues [80,81].