FLT3LG and neoplasm: The number of tumor infiltrating Tregs was reduced after systemic delivery of PC61 (p<0.001, Fig. 6E) and the percentage of Tregs was also significantly reduced in dLN and spleen, (p<0.001, Fig. 6F–G) irrespective of whether the mice were treated with saline or with Ad-Flt3L and Ad-TK.