By dividing and differentiating, a single cell can develop into a complex multicellular organism such as a human being. Transcription factors are proteins that play an important role in the development by regulating the activity of genes. In this project, three transcription factors and their roles in the development of a specific tissue in zebrafish were investigated. By using new methods, I revealed previously unknown regulatory interactions, which improved our understanding of the roles of the three transcription factors. The findings could lay the foundation for the development of new medical diagnostics and therapies, since all three transcription factors have been implicated in diseases such as cancer or Alzheimer’s disease.