All FVIII:C levels were measured with a chromogenic method (STA-R Max3 analyzer ; TriniCHROM FVIII:C reagent – Stago) by using bovine coagulation factors X and IXa that do not interfere with emicizumab.7, 8, 9In same plasma samples, thrombin generation assays (TGA) were performed by using low concentration of tissue factor (1 pM) as suggested for the TGA in hemophilia A patients.10TGA were performed before the surgery without rFVIII-Fc and throughout rFVIII-Fc infusions (Fig. 1B). Here, F8 is linked to hemophilia A.