Gar15-13 PDX treated for 10 days with NVP-CGM097 alone or in combination with fulvestrant showed reduced Ki-67 staining compared to vehicle-treated tumours, although no significant difference was observed between the NVP-CGM097 only arm and the combination arm (vehicle vs NVP-CGM097 p < 0.01; vehicle vs combination p = 0.011, all other pairwise comparisons not significant at α = 0.05) (Fig. 5d). This evidence concerns the gene MKI67 and neoplasm.