FXII can be cleaved sequentially at two sites, Arg353 and Arg334, with the second cleavage liberating the light chain and forming β-FXIIa.

[6] The structure of the FnI-EGF-like tandem domain of coagulation factor XII has been solved by X-ray crystallography.

[7][8] Crystal structures of the FXII light chain have also been determined, both unbound (β-FXII) and bound (β-FXIIa) to inhibitors.

[12] FXII also plays a role in diagnostic coagulation assays called activated partial thromboplastin times (aPTT).

The protein seems to be involved in the later stages of clot formation rather than the first occlusion of damages in the blood vessel wall.

[19] As a result, the main concern related to factor XII deficiency is the unnecessary testing, delay in care, worry, etc.

[24] Currently produced QuikClot products, produced and marketed primarily for use in battlefield medicine to treat penetrating trauma (such as gunshot wounds and stab wounds), and other injuries that are known to commonly cause exsanguination (such as blast injury), are used with the overarching goal of increasing the time between the blood loss occurring, and the patient succumbing to the blood loss.

The purpose of increasing this time is so that the patient may reaching a higher level of medical care before succumbing from their injuries.

This coating, when applied to an open wound via the application of the bandages, directly promotes blood clotting by activating Factor XII in the coagulation cascade.

[26][27] This coating is widely considered amongst combat medics to be vastly superior to the older QuikClot powder formulation, which was poured into wounds, due to the fact that the older formulation used bead-form Zeolite, a mineral which promotes the coagulation cascade, due to the fact that the reaction between the Zeolite powder and the blood inside the wound site was an Exothermic one, sometimes so intensely that it caused cases of second degree burns on the inside surface of the wound.