MET and neoplasm: Immunohistochemical evaluation of the ratio of cells for the nuclear antigen Ki67 has been one of the most widely used strategies for determining cell survival and chemosensitivity in tumor biological research.19 As expected, in the IHC data for Ki-67 staining, highly proliferative liver tumor cells were repressed upon celastrol administration, with significant reduction of the proliferation index) from tumors in AKT/c-Met mice (Fig. 3A and C).