Epithelial cells require adhesion to the extracellular matrix for survival, and in the absence of
adhesion they undergo apoptosis (anoikis). This is distinct from apoptosis induced by
extracellular death ligands, such as tumor necrosis factor, which result in direct activation of
caspase 8. Bid is a member of the BH3-only subfamily of the Bcl-2 proteins and is important
for most cell types to apoptose in response to Fas and tumor necrosis factor receptor
activation. Caspase 8 cleaves full-length Bid, resulting in truncated p15 tBid. p15 tBid is …