Taking advantage of polychromatic flow cytometry (which allows the simultaneous identification of multiple T-cell subphenotypes based on the expression of specific markers including CD3/CD4/CD45RO/CD45RA/CCR7/CCR5/ CXCR3/HLA-DR), Ammirati and colleagues show that several specific CD4+ subphenotypes of circulating effector memory T cells (TEM) are preferentially associated with human atherosclerosis. The gene discussed is CD4; the disease is atherosclerosis.