HCMV plaque formation is increased in PLSCR1-KO cells compared to parental cells. HEL, 36T-3, PLS1KO-A, and PLS1KO-B cells were infected with a 10-fold series of diluted HCMV and incubated for 6 to 10 days. The cell monolayer was fixed and then stained with methylene blue. Plaques were counted microscopically under low power, and the PFU were measured. The Data represent the average relative values from four experiments with duplicate cultures per experiment, and the error bars indicate the standard deviations. **, P < 0.01 by Student's t test.