ID proteins function to regulate the activities of E proteins, transcription factors that are essential for normal lymphocyte development. A recent study in The Journal of Immunology (April 2017) by Dr. Yuan Zhuang and colleagues demonstrates that ID proteins also function as tumor suppressors. They found that mice lacking Id2 and Id3 expression in T lymphocytes rapidly develop T cell lymphomas representing two types of innate-like T cells. These mouse T cell tumors have features that are closely related to those of the analogous human T cell tumors, suggesting that the mice may provide a useful model for better understanding and treating the human disease. Read the article here.