Involvement of STAT3 in immune evasion during lung tumorigenesis.

In a recent study, we have shown that STAT3 expressed by tumor cells blunts antitumor immunity during carcinogen-induced lung tumorigenesis. STAT3 inhibits the production of pro-inflammatory chemokines and MHC Class I chain-related gene A. In contrast, STAT3 promotes the expression of MHC Class I molecules. Consequently, STAT3 promotes tumor cell resistance to NK cell-mediated cytotoxicity.