The Notch receptor signaling pathway is activated by the binding of the transmembrane receptor Notch (N) to transmembrane ligands, Dl or Ser, presented on adjacent cells. This results in the proteolytic cleavage of N, releasing the intracellular domain (NICD). NICD translocates into the nucleus, interacting with Su(H) and mam to form a transcription complex, which up-regulates transcription of Notch-responsive genes. Notch cell-cell signaling is important in many cell fate decisions during development and in tissue homeostasis. (Adapted from FBrf0225731 and FBrf0192604).