Inhibitor of DNA-binding-2 (Id2) is a member of the Id proteins which belong to the helix-loop-helix (HLH) protein family. The Id protein functions by binding to specific transcription factors and preventing their dimerization and DNA binding (1-3). Id2 interacts with a wide variety of transcription factors including E proteins (5), TCS (4), Pax (6) and the tumor suppressor Rb (1). Id2 has been shown to be important in regulating cellular differentiation, proliferation, development and tumorgenesis (7-9). In tumor cells, increased levels of Id2 functionally inactivate Rb, leading to cellular transformation and cancer (10,11). Id2 is therefore a promising therapeutic target for treatment of cancer (12).