Final answer:
The Notch Intracellular Domain (NICD) activates the transcription of target genes involved in cell differentiation, proliferation, and apoptosis after being cleaved from the Notch receptor and entering the nucleus.
Step-by-step explanation:
The Notch Intracellular Domain (NICD) plays a vital role in the Notch signaling pathway, which is a mechanism of intercellular communication that regulates cell differentiation processes. After ligand binding to the extracellular domain of the Notch receptor, a conformational change occurs that leads to the cleavage of the NICD. This allows NICD to enter the nucleus, where it acts as a transcription factor to activate the transcription of target genes. These target genes are involved in cell fate decisions, and their expression leads to various outcomes such as cell differentiation, proliferation, and apoptosis.