SensiStain Anti-Ki-67 Antibody can be used to detect the presence, absence, or level of expression of Ki-67. As a nuclear, non-histone protein that is expressed only during active phases of the cell cycle (G1, S, G2 and M), but not in the resting phases (G0 and G1 early phase); Ki-67 is linked to cell proliferation. It is used as a marker to grade tumor proliferation rates.