Tumor progression may be caused by Th1/Th2 mixed reaction or Th2 dominant response [123], relying on TGF-β and IL-10 to transform Th1 cells into Th2 cells to reverse the anti-tumor effects of CD8+ cytotoxic T cells and CD4+ Th1 cells, which is thought to be a tumor immune escape mechanism [124]. The gene discussed is CD4; the disease is neoplasm.