A gene regulatory network (GRN) is a collection of molecular regulators that interact with each other and with other substances in the cell to regulate gene expression. These networks control when, where, and how much of a gene product, such as a protein, is produced. GRNs are essential for processes like development, cell differentiation, and response to environmental changes. In a GRN, various elements such as transcription factors, enhancers, and promoters work together to influence gene activity. By understanding these networks, scientists can gain insights into complex biological processes and diseases, including cancer and genetic disorders.