CCR4 and cancer: At present, several CCR4 antagonists have undergone evaluation in clinical trials, however, mogamulizumab is the sole CCR4 antagonist approved for cancer treatment, specifically for treating T cell lymphomas.385 Besides, mogamulizumab effectively induced depletion of FoxP3+ Tregs in patients with solid tumors.386 In a phase I clinical trial, mogamulizumab was safe and well-tolerated, without any dose-limiting toxicity (Table 11).