RNAi induces a G2/M block and apoptosis. Histograms showing PI staining of DNA content, with the x-axis reflecting DNA content and the y-axis the cell number. Arrows indicate sub-G1 cells (apoptotic). Flow cytometric determination of cell cycle distribution of LNC cells following 24 hr (A-C) or 42 hr (D-F) of treatment: Control (A) and (D), scrambled IL-10 dsScr (B) and (E), RNAi IL-10 (RNAi) (C) and (F). The distribution of cells in each phase of the cell cycle following treatment was summed to give the percentage of cycling cells. The percentage of apoptotic cells is expressed as a percentage of the whole gated population.