Location of vWD type 2M and type 2B mutations in the vWF A1 domain. The α-carbon trace is shown for the vWF A1 domain, modeled on the crystallographic structures of the homologous α_Mand α_L A domains as described in Materials and Methods. The locations are shown of residues known to be mutated in patients with vWD type 2M (G561, I662, F606, and ▵R629-Q639) and vWD type 2B (R543, R545, W550, V551, V553, R574, and R578).