The main role of the liver in the body is to process nutrients and filter toxins from the blood. It plays a crucial part in metabolism, converting nutrients from the digestive tract into essential substances that the body can use for energy, growth, and repair. The liver also produces bile, which aids in the digestion and absorption of dietary fats. Additionally, it regulates blood sugar levels by storing and releasing glucose as needed. Overall, the liver is vital for maintaining homeostasis and supporting various bodily functions, emphasizing its importance in overall health.