Which of the following factors are deficient in patients under warfarin therapy:

Clotting factors 2,7,9,10 are vitamin K dependent factors. Six of the proteins involved in clotting require conversion of a number of glutamic acid residues to γ-carboxyglutamic acid residues before being released into the circulation, and hence all six are vitamin K-dependent. These proteins are factors II (prothrombin), VII, IX, and X, protein C, and protein S. Coumarin derivatives such as dicumarol and warfarin are also effective anticoagulants. They inhibit the action of vitamin K, which is a necessary cofactor for the enzyme that catalyzes the conversion of glutamic acid residues to γ-carboxyglutamic acid residues. Reference: Ganong’s Review of Medical Physiology T W E N T Y - F I F T H   E D I T I O N page no 566,567