The frequencies of Treg lymphocytes, defined by the CD3+CD4+CD25+CD127− phenotype, were significantly different across patient groups, (p = 0.008), being greatest in patients with sepsis, (median 11.7%, IQR 7.5–14.6%), than with infection (Median 7.8%, IQR 6–10%) and healthy controls (Median 7.7%, IQR 6.7–9.2%). The gene discussed is CD4; the disease is infection.