There is considerable interest in the role of Fas protein as it induces apoptotic cell death
when ligated by its natural ligand (FasL). Interaction between Fas and FasL is a crucial
mechanism for clonal deletion and immune tolerance and privilege, control of T cell
expansion during immune responses and killing by cytotoxic T lymphocytes. Loss of function
of the system can block lymphocyte apoptosis and cause lymphoproliferation and
autoimmunity but, when the system overfunctions, it can end to tissue injury and destruction …