To gain a better understanding of the function of ATG5 in NPC immune cell infiltration, further studies showed that in HNSCC samples with high expression of ATG5, CD8+ T cell, memory resting CD4+ T cell, activated mast cell, monocyte, macrophage M2, and other immune cells were significantly reduced, and only T cell regulatory (Tregs) and macrophage M0 cells increased significantly, respectively (p < 0.05, Figure 5A). This evidence concerns the gene CD4 and head and neck squamous cell carcinoma.