PHA-stimulated primary CD4⁺ T lymphocytes (A) and SupT1 cells (B) were mock-infected or infected with HHV-7 in the presence or absence of PFA, and cell cycle was analyzed by flow cytometry, at 48-hour intervals, after staining of the DNA content with propidium iodide. The X axis shows the DNA content in a linear scale, determined based on fluorescence due to propidium iodide staining, and the Y axis reflects the relative number of cells. The percentage of cells in the G₁(2n) and G₂+M(4n) phases of the cell cycle for each experimental point are reported in Tables 2 and3. These results are representative of four separate experiments performed in duplicate.