The 3-dimensional FVIII structure clarified the molecular basis of FVIII variants causing hemophilia A. The 2 earlier FVIII crystal structures used for the 2013 database (PDB IDs 2R7E and 3CDZ)28,29 are superseded by an improved one (PDB ID 6MF2),25 in all 3 of which the B domain is not present. Here, F8 is linked to hemophilia A.