The MMTV-atx transgenic construct contains the 1.54 kb MMTV LTR and the full-length human atx cDNA linked to the KCR fragment containing the exon II (E2), intron II (I2), exon III (E3), and polyadenylation signal (rbGpA) derived from rabbit beta-globin. Two MMTV-atx (#ATX 20 and #ATX 21) founders passed the transgene through the germ line. (J:149661)