Transcription factors are proteins that help regulate the process of transcription, where DNA is copied into RNA. They bind to specific sequences of DNA near genes, either promoting or inhibiting the expression of those genes. This regulation is crucial for controlling various cellular functions and responses. These factors can respond to signals from the environment or other cells, allowing organisms to adapt to changes. For example, in humans, transcription factors play a key role in development, immune responses, and even the cell cycle. Their proper functioning is essential for maintaining health and preventing diseases.