TNF and breast cancer: A generated immunotoxin (KD = ~0.45 μM) composed of an scFv derived from the LeY-specific mAb B1 and tumour necrosis factor α (TNF-α), a protein that can induce cell death upon binding to cell surface receptors, was specifically cytotoxic in vitro and in vivo in TNF-α-sensitive MCF-7 human breast cancer cells xenograft mice 111.