Cellular response refers to how cells react to various stimuli, such as hormones, nutrients, or environmental changes. This process involves signaling pathways that transmit information from the cell surface to its interior, leading to specific actions like growth, division, or apoptosis (cell death). Different types of cells have unique responses based on their functions and the signals they receive. For example, immune cells respond to infections by activating and proliferating, while muscle cells may respond to exercise by increasing in size and strength. Understanding cellular response is crucial for fields like medicine and biotechnology.