CD4 and autoimmune disease: Studies related to human/mouse have shown that abnormal Tfh is not only associated with autoimmune diseases, but also a pathogenic factor of autoimmune diseases.[44] Studies have shown that CD4 T cells can promote tumor regression in cancer through a variety of mechanisms, including IL-2 secretion, enhancement of tumor-specific CD8 T cell function, or direct elimination of cancer cells.[45] According to our results, we inferred that the hub genes may be involved in the occurrence of THCA through regulating the activation of Tfh and CD4 T memory cells.