Gene regulation is the process by which cells control the expression of their genes. This means that not all genes are active at all times; instead, cells can turn genes on or off depending on their needs. This regulation is crucial for processes like development, response to environmental changes, and maintaining cellular functions. There are various mechanisms of gene regulation, including transcription factors, which are proteins that bind to specific DNA sequences to enhance or inhibit gene expression. Other methods include epigenetic modifications, which alter the structure of DNA without changing the sequence, and RNA interference, where small RNA molecules can block the translation of specific mRNAs into proteins.