Fig. 1

Frequency of CD4+ cells and CD4 + CD28− cells. Frequency of CD4+ cells within CD3+ cells in all subjects (a) and subgroups by their age (≤50 or > 50 years old) (b) or CMV serostatus (c). Frequency of CD4 + CD28− cells within CD4+ cells in all subjects (d) and subgroups by their age (≤50 or > 50 years old) (e) or CMV serostatus (f). Lines show the median. Patients with converted CMV serostatus during study period were not included in (c) and (f). HC, healthy controls; Tx, transplantation