Cytofluorimeter analysis. Cells were analyzed for CD3 expression and CFSE incorporation. T-cells are selected with CD3+ marker, on the y axis the group of cells above the horizontal line are CD3+. On the x axis, the amount of CFSE indicates if cells replicated or not: for each cell division the amount of CFSE incorporated in DNA is reduced by half. The upper left panel (red circle) contains T-cells which have replicated.