CD28 and coronary artery disorder: Consistent with the increased frequencies of CD28hiCD161hi Vγ9Vδ2 T cells in the CHD group observed by FACS analysis (Fig. 3), expression of KLRB1 (encoding CD161) and CD28 was higher in Vδ2+ cluster c3, c5, and c6 cells of the CHD group as compared to controls (Fig. 5b).