R6/2 [B6CBA-Tg (HDexon1) 62Gpb/1 J] mice, which express exon 1 of the human mutant Huntington’s disease gene containing 160 CAG repeats, under the control of the human IT15 promoter, and wild-type (WT) littermates were generated by crossing ovarian-transplanted hemizygous females with B6CBAFI/J males. The gene discussed is HTT; the disease is Huntington disease.