FOXP3 and neoplasm: Next, in order to assess whether Itgβ8 expression by Tregs confers their abilities to control the anti-tumor immune responses by providing a bioactive source of TGF-β, we first selectively ablated Itgb8 in Tregs, using Foxp3-Cre Itgb8fl/fl mice (Foxp3ΔItgβ8).