FOXP3 and cancer: For example, in a study of Interferon regulatory factor 4 (IRF4) with effector Treg differentiation and immune suppression in cancer, Foxp3EGFP-Cre-ERT2 mice were crossed with Irf4-floxed mice to allow for the specific deletion of Irf4 in Foxp3+ cells following TAM treatment [49].