Researchers became interested in activated protein C when they found that patients with sepsis had abnormally low levels of it.

Wilson notes to House that he would've ordered protein C as well.

Patients with certain blood conditions (protein C or S deficiency) may be at greater risk.

If approved, the genetically engineered version of a substance from human cells, called activated protein C, will be sold under the name Zovant.

These include gradual increase starting from low doses and supplemental administration of protein C (pure or from fresh frozen plasma).

It is in this form that 85-90% of protein C circulates in the plasma as a zymogen, waiting to be activated.

Activated protein C is found at levels approximately 2000 times lower than this.

Activated protein C also provides much protection of endothelial barrier function.

Binding of activated protein C to protein S leads to a modest increase in its activity.

For example, mutations in protein C, when leading to insufficient protein levels or activity, predispose to thrombosis.