Description: This 4H1HES monoclonal antibody reacts with human Hes1, a 30-kDa basic-helix-loop-helix transcriptional repressor. Hes1 is expressed in thymocytes, as well as neural, retinal, liver, and pancreatic tissues. Expression of Hes1 is controlled by Notch signaling, and thus plays an important role in T cell development. This regulation by Notch is also critical for neural stem cell differentiation and neurogenesis. Reports have demonstrated that Hes1 antagonizes transcription of MASH1, a basic-helix-loop-helix factor involved in neuronal determination. Finally, Hes1 has been associated with Notch-induced T cell acute lymphoblastic lymphoma and other cancers.