CD4 and gastric cancer: Studies of gastric cancer models have found that although CD4+FoxP3−T cells, CD4+FoxP3−CTLA-4 T cells, and CD4+FoxP3−PD-L1−T cells are close to tumor cells, However, the distance between CD68+CD163−HLA-DR+(M1) macrophages and tumor cells makes it difficult for them to perform the ideal antigen presentation function [76].In a model of head and neck squamous cell carcinoma, PD-1+ helper T cells colocalized with CD163+TAMs within tumor tissue, and this colocalization significantly shortened overall survival compared with other subpopulations [77].