MKI67 and neoplasm: Moreover, as demonstrated by immunohistochemical (IHC) analyses performed in mice‐derived tumor sections, FK866 promotes a reduction of TRF2 expression, associated with increased levels of H2AX phosphorylation (γH2AX) and 8‐hydroxyguanine (8‐OHdG), and decreased Ki67 proliferation marker (Figure 6f).