CCR7 and head and neck squamous cell carcinoma: We further re-examined tumor-infiltrating Tregs according to both CD45RA and CCR7, and confirmed most Tregs showing a CD45RA−CCR7− effector/memory phenotype, which is in accordance with the results on Tregs in squamous cell head/neck carcinoma regarded as ‘effector’ phenotype.19 Collectively, these expression profiles reveal that CD45RA−CCR7− tumor-infiltrating Treg subset exhibits a phenotype for effector functional features.