MKI67 and neoplasm: Immunohistochemical analysis of tumours taken at humane endpoints or at the end of the six-week study revealed a 65% reduction in tumour cell proliferation in mice treated with HM30-tesirine, with 28 ± 9.4% of cells staining positive for Ki67, compared to 83 ± 8.4% in control tumours (n = 3 individual tumours; p = 0.0016; Fig. 6g,h).