From the analyses of tumor samples, we observed that AURKA inhibitor treatment selectively induced caspase-3 activation and inhibited tumor cell proliferation in RB1−/− lung cancer xenografts in mice without apparent body weight changes (Fig. 2j, k; Supplementary Fig. 5a–h; Supplementary Fig. 6a–d), indicating that RB1 loss greatly increased the vulnerability of the cancer cells to AURKA inhibition in vivo. Here, RB1 is linked to cancer.