ID2 and neoplasm: In order to implement an experimental scheme in which Treg-specific expression of Id2 commences simultaneously with tumor implantation, we employed an inducible model of temporal expression of Id2 in Treg cells by crossing Id2EmGFPFoxp3YFP−Cre mice with PCMV-TetR mice (resultant mouse called TetR-Id2EmGFPFoxp3YFP−Cre).