Interaction of fibrin(ogen) with platelet αIIbβ3 during different phases of thrombus development. (A) Chart showing the interactions of platelet αIIbβ3 with fibrinogen, fibrin monomer and polymer, cross-linked fibrin, and fibrinogen degradation products D100, D98, and D-dimer, as a function of thrombus maturation. Interactions mediated by fibrinogen γ404-411 with the αIIbβ3 RGD binding pocket are indicated by plus signs, and those that are not yet defined are indicated by ND. (B) Schematic of fibrinogen (adapted from Yang et al⁹  and Springer et al⁶  with permission) highlighting the γ406-411 region and indicating the D100 and D98 plasmin fragments of fibrinogen. (C) Schematic of cross-linked fibrin, highlighting the location of the fibrinogen γ-chain residue Lys406, the FXIIIa-mediated cross-links, and the plasmin fragment D-dimer (adapted from Mosesson et al¹⁰  with permission; ©1989 National Academy of Sciences).