Moreover, the antitumor effect of AdSOCS-1 was significantly attenuated by PD-L1 Fc-fusion protein administration <i>in vivo</i>, suggesting that the effect of AdSOCS-1 is mainly attributable to enhancement of tumor immunity.
The results indicate that <i>Socs1</i>-deficient Tregs tend to convert into ex-Tregs under the inflammatory conditions in which APCs are highly activated, and that SOCS1 could be a useful target for enhancement of anti-tumor immunity.