Abstract:Type 17 T helper cells (Th17) are novel subsets of CD4+ effector T cells discovered recently which are different from the traditional type 1 and type 2. They are mainly differentiated from initial T cell precursor. Tumor microenvironmental cytokines can recruit CD4+ Th17 cells from the peripheral blood into tumor sites. And the differentiation of Th17 cells is also affected by tumor microenvironmental factors. Tumorinfiltrating Th17 cells play a dual role for tumor growth in both pro and antitumourigenic processes. A further understanding of the activities of Th17 cells will provide a new breakthrough point for the researches of cancer immunotherapy.

Key words:Neoplasms,Inflammation,Th17 cell