MKI67 and Kaposi's sarcoma: The effect of NGR-Dau conjugates and free Dau on proliferation was evaluated in the primary tumor by proliferation index, presented by the percentage of proliferation marker (KI-67) positive cells out of all cells per field of view in subcutaneous Kaposi’s sarcoma and orthotopic HT-29 human colon primary tumors (Fig. 7a,b).