Whilst not all CD25+ cells are FoxP3+ Tregs (75%–80% in our infection model) and FoxP3+Treg populations can be rapidly induced following CD25+ depletion during infection [27], a single antibody treatment with anti-CD25 clone PC61 can significantly reduce FoxP3+ cells by 70% [28], with reduced FoxP3+ cells persisting in the face of ensuing inflammation for two weeks [27]. Here, FOXP3 is linked to infection.