Where does veto collide?

In immunology, a veto cell is a cell that suppresses an immune response directed against itself: when a T cell recognizes a veto cell, the veto cell inactivates or kills that responding T cell rather than being destroyed, enforcing tolerance. Pamela Fink, Richard Shimonkevitz, and Michael Bevan's 1988 review Veto cells set out the evidence for this one-way suppression and its role in self-tolerance and transplantation. The referent is a cellular mechanism of immune suppression, demonstrated in culture and in grafts, sharing only the blocking metaphor with the political power to nullify a decision.[1]

Unit

The capacity of a cell to inactivate the immune cells that recognize it

Recovery means

Not applicable

Measured by

Demonstrated in culture and transplant models by the specific inactivation or deletion of responding T cells that recognize the veto cell

In political science, a veto is the power to block a change to the status quo, and a veto player is any actor (a chamber, a party, a court, a president) whose assent is necessary for policy to change. George Tsebelis's 2002 Veto players: How political institutions work shows that the number of such players, and the ideological distance between them, governs how far policy can move: more veto players mean greater gridlock and stability. The referent is a structural capacity to block collective decisions, and it is a wholly different construct from the immune cell that bears the same name.[2]

Unit

The capacity of an actor to block a change to the policy status quo

Recovery means

Not applicable

Measured by

Counted as the number and ideological spread of actors whose agreement is required to change policy, predicting policy stability