The human MAPT sequence from exon 1 to exon 14 (NCBI Reference Sequence: NG_007398 with H2 haplotype) and a loxP/FRT flanked neomycin resistance gene replaced the entire genomic sequence (from exon 1 to exon 14) of murine Mapt via homologous recombination. Cre-mediated recombination removed the neomycin gene. Western blot analysis confirmed the expression of all human tau isoforms.