[5] This protein may play a role in cell growth, senescence, and differentiation.

[10] ID1 has been shown to interact weakly with MyoD[5][11][12][13][14][15][16] but very tightly with ubiquitously expressed E proteins.

to form active transcription complexes so by sequestering E proteins, Id proteins can inhibit tissue restricted gene expression in multiple cell lineages using the same biochemical mechanism.

[18] ID1 can be used to mark endothelial progenitor cells which are critical to tumor growth and angiogenesis.

[23][24] This article incorporates text from the United States National Library of Medicine, which is in the public domain.