CD4 and tongue squamous cell carcinoma: For instance, hepatocellular carcinoma patients harbor significantly more peripheral Bregs compared to healthy controls (93); malignancy in non-small cell lung cancer is associated with an increased frequency of IL-10-producing Bregs, CD4+CD25+/highCD127low/− Tregs, and MDSCs (94); patients with tongue squamous cell carcinoma, gastric cancer, and colorectal cancer also exhibit a higher frequency of Bregs within the tumor itself compared to unaffected neighboring tissues, with numbers positively correlated with an increased frequency of Tregs (91, 95, 96).