Extended data 2: NKR expression in CD8+ and CD4+ T cells defined by CD27/CD28.
Expression of NK cell receptors (NKR) on a) CD8+ and b) CD4+ T cells assessed by flow cytometry on PBMCs from 22 healthy donors (median age = 52, range 25–83). Total CD8+ and CD4+ T cells were stratified into three subsets according to CD27/CD28 expression as shown in Extended Data 1a.