The Notch signaling pathway provides a basic means of cell-to-cell communication to regulate cell-specific responses during the development of virtually every tissue and organ in our body.
Not surprisingly, dysregulation of the Notch pathway results in complex developmental syndromes and/or diseases that include cancer. In fact, genetic studies have shown that the Notch pathway is highly sensitive to gene dose, which was first discovered in the fruit fly Drosophila melanogaster.
Subsequent studies found that human birth defects and syndromes are linked to both haploinsufficiency and/or dominant genetic variants in three NOTCH receptors (NOTCH1/2/3), four ligands (DLL3/4 and JAG1/2), and the RBPJ transcription factor.
Thus, both Drosophila and vertebrate animal models can be used to understand how Notch pathway dysregulation causes tissue-specific human developmental syndromes.