Regulators require that a study demonstrate direct patient (…

Regulators require that a study demonstrate direct patient (e.g. longer life expectancy) benefit for a product (drug, device) to be approved. A sponsor may argue that another result may indicate that the required benefit is likely to occur. This other result is called a:

The biochemical pathway that converts fatty acids into pyruv…

The biochemical pathway that converts fatty acids into pyruvate is catalyzed by a series of enzymes.  When the level of pyruvate in the cell is high, this inhibits the function of the first enzyme in the pathway.   Based on this information, pyruvate could best be described as a: