Figure 1 Structure of ADAMTS13 Left inset adapted with permission from Akiyama, M., Takeda, S., Kokame, K., Takagi, J. & Miyata, T. Crystal Structures of the noncatalytic domains of ADAMTS13 reveal multiple discontinuous exosites for von Willebrand factor. Proc. Natl Acad. Sci. USA 106, 19274–19279 (2009), National Academy of Sciences. Right inset reproduced with permission from Muia, J. et al. Allosteric activation of ADAMTS13 by von Willebrand factor. Proc. Natl Acad. Sci. USA 111, 18584–18589 (2014), National Academy of Sciences Kremer Hovinga, J. A. et al. (2017) Thrombotic thrombocytopenic purpura Nat. Rev. Dis. Primers doi:10.1038/nrdp.2017.20