Probable binding sites of monoclonals 314.1, 314.3, 10E5, 312.6, and 312.8 in the GPIIb β propeller domain. N-terminal repeats (“blades”) of the propeller 1 to 7 and the CAP subdomain²⁶  are shown schematically. The binding site shown for 10E5 is based on the crystallographic data of Xiao et al.¹⁸  Proposed binding sites for the other 4 mAbs are based on their reactions with chimeric GPIIb/IIIa (Table 1) and the results of competitive binding studies (Table 2).