The impact of CMV serostatus on the distribution of subsets and expression of CD244, CD160, and PD1. The proportion of T cells expressing PD1, CD160, and CD244 were measured by flow cytometry in patients with CLL and healthy controls matched for CMV serostatus. Significant increases in the expression of CD244 (A) and CD160 (B) were observed independently of CMV serostatus. (C) In contrast, expression of PD1 was only increased comparing CMV− patients and controls. (D) CD3⁺CD8⁺CCR7⁻ cells are expanded in CLL irrespective of CMV serostatus. (E) There is a reduction in naive and central memory cells because of both CLL and CMV seropositivity. The presence of CLL skews the T-cell repertoire toward a T_EM phenotype, whereas the presence of CMV leads to an expansion of T_EMRA cells.