We subsequently evaluated the antiproliferative effect of combined treatment with HDM201 and Remodelin in GC cell lines and observed remarkable synergistic growth inhibitory activity, i.e., combination index < 1, at most or all concentrations tested in GC cell lines harboring wild-type p53 (Fig. 7H), while p53-mutant cells were resistant to MDM2 inhibitors (Additional file 1: Fig. S10). The gene discussed is TP53; the disease is gastric cancer.