The anti-CCR4 antibody mogamulizumab reduces the number of CCR4+ Tregs in patients with solid tumors.127 128 The depletion of Tregs was confirmed in patients treated with mogamulizumab plus an anti-PD-1 antibody (nivolumab)129 in a clinical trial, suggesting that this combination is a promising option in combination cancer immunotherapies. Here, CCR4 is linked to cancer.