When the levels of A??x-42 (Figure 3C) and A??1-42 (Figure 3D) were analyzed from the same aliquots of plasma, we found that the levels of A??1-42 species were generally lower than those of A??1-40 species and that the levels of A??x-42 were likewise lower than those of A??x-40 (compare Figure 3A and B with Figure 3C and D).