ICB administered i.t. reduced proliferating Tregs (CD4+FoxP3+Ki-67+) within the tumor compared to other ICB administration methods (Fig. 5G), an effect attributable to the particular aCTLA-4 mAb isotype used (4–6) and higher CTLA-4 surface expression on Tregs (fig. Here, FOXP3 is linked to neoplasm.