Cell phase: The phase in a cell cycle that corresponds to a defined DNA content range determined by flow cytometry measurements that includes G1 (gap phase 1), S phase (the DNA synthesis phase), and G2/M (the gap 2 and mitosis phases; here abbreviated G2). Different portions of S phase are obtained by dividing the cell cycle into seven DNA content windows based on the relative peak positions corresponding to the G1 and G2 cell cycle fractions. The G1 peak position is routinely set at "60" relative UV fluorescence, thus producing G2 peak values in the 116-120 range