In addition, overexpression of Sox4 was detected in all types of lung cancer, including SCLC and NSCLC, and the antigen peptide derived from Sox4 was capable of activating CD4+ and CD8+ T cells recognizing Sox4 positive lung tumor cells, by which Sox4 might serve as a vaccine antigen candidate for the treatment of both SCLC and NSCLC [81]. Here, CD4 is linked to lung cancer.