The Notch gene encodes a transmembrane receptor that gave the name to the evolutionary highly conserved Notch signaling cascade. It plays a pivotal role in the regulation of many fundamental cellular processes such as proliferation, stem cell maintenance and differentiation during embryonic and adult development. After specific ligand binding, the intracellular part of the Notch receptor is cleaved off and translocates to the nucleus, where it binds to the transcription factor RBP-J. In the absence of activated Notch, RBP-J represses Notch target genes by recruiting a corepressor complex. Here, we review Notch signaling with a focus on gene regulatory events at Notch target genes. This is of utmost importance to understand Notch signaling since certain RBP-J associated cofactors and particular epigenetic marks determine the specificity of Notch target gene expression in different cell types. We subsequently summarize the current knowledge about Notch target genes and the physiological significance of Notch signaling in development and cancer.