The lack of CD28 expression in these cells indicates that this pool constitutes most likely a subset of cytotoxic CD4+CD28null T cells, which has previously been associated with atherosclerosis as they have been detected in peripheral blood of patients with CAD.30,73 Although the presence of a similar TCR clone as observed in peripheral CD4+CD28null cells was found in bulk coronary artery tissue,30,73 we can now confirm the presence of these cells on a single-cell level suggesting a functional role in patients with CVD. Here, CD28 is linked to atherosclerosis.