Location of the types 2B, 2M, and 2A mutation sites in homology models of the vWF-A1 and vWF-A2 domains. Each of the vWF-A1 and vWF-A2 domains is shown in two orthogonal perspectives rotated by 90° along the vertical axis. The central β-sheet is seen edge-on in both views. The mutation residues are identified by spheres at their α-carbon atom. The protein backbone is represented by a ribbon. The eleven residues deleted in the type 2M “Milwaukee” mutation are shown as the cyan ribbon in the vWF-A1 model.