Summary of transgenic lines. A, Diagram of hAPP indicating the mutations expressed in transgenic mice. FAD-linked mutations are commonly referred to by place of discovery or residence of affected kindred. The 670/671_KM→NL double mutation affects a large pedigree in Sweden (Mullan et al., 1992), and the 717_V→F mutation was identified in Indiana (Murrell et al., 1991) (numbers refer to amino acids in APP770). Mutations at position 717 are often collectively referred to as “London mutations” based on the first report of the FAD-linked 717_V→I mutation (Goate et al., 1991); however, the latter mutation was not studied here. The sequence of Aβ is indicated inbold in single-letter amino acid code.KPI, Kunitz-type protease inhibitor domain. Elements are not drawn to scale. B, Relative levels of cerebral transgene expression (values in parentheses) were determined in different lines of PDGF-hAPP mice as illustrated in Figure 2. The expression level in line I63 was arbitrarily defined as 1.0.