<p>Female nude mice bearing MDA-MB-231 tumors were treated with either vehicle (control) or the compounds AuD6 and AuD8 at 1 mg kg<sup>−1</sup> d<sup>−1</sup>. <b>A,</b> Inhibition of xenograft growth by both complexes. Tumor volumes were measured every other day using a caliper. Points represent the mean ± SD (bars) of seven mice per group. The insert depicts representative tumors from each treatment group; * = p<0.05. <b>B</b>, If only the most responsive mice are considered, the xenograft growth inhibition is greater. The insert shows average weights of mice over time; ** = p<0.01. <b>C</b>, Immunohistochemical p27 and TUNEL staining of tumor samples indicates proteasome inhibition and apoptosis as a result of both compounds. Stronger p27 staining is observed following AuD8 treatment, and more TUNEL positive cells are observed following AuD6 treatment. Brown colored cells are considered positive.</p