Furthermore, the double Cre mice (HSA-Cre;PDGFRα-CreER;ARL2/Y), with ablation of AR in both myofibers and mesenchymal progenitors, exhibited a greater reduction in LA/BC mass compared with single Cre mice (HSA-Cre;ARL2/Y or PDGFRα-CreER;ARL2/Y). The gene discussed is ARL2; the disease is breast cancer.