<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  Explain the function of the human immune system. Context: The human immune system acts as the body's defense mechanism against harmful pathogens by producing antibodies and initiating immune responses. Answer: [/INST]It is responsible for protecting the body against harmful pathogens, such as bacteria, viruses, and parasites, by producing antibodies and mounting immune responses.</s>