This projection, based on a previously solved structure of the activated FXIIIa A₂ dimer,⁸  shows the K468-Q469 plasmin cleavage site in red and its proximity to the active-site cysteine in green. This site is cleaved only in activated FXIIIa, not FXIII zymogen, and this cleavage event inactivates FXIIIa. See Figure 2B in the article by Hur et al that begins on page 2329.