Ki67 staining (cancer cell proliferation) (Extended Data Fig. 6a) confirmed that at the end point, gemcitabine is significantly decreasing the number of Ki67 positive tumor cells (P = 0.0185) and that this is further decreased in combination with PXS-5505 (P = 0.0089), underpinning the significantly decreased tumor growth observed in the combination therapy arm, likely through sustained perfusion of agents into the tumor. This evidence concerns the gene MKI67 and cancer.