Brief Description of the Human Immune System

Due to the invention of mRNA vaccines and tumor immunotherapy, immunology has become the hot spot in recent years. It is believed that the immune system in the human body can protect us from pathogens and tumors by self-nonself discrimination. Here, we briefly review the composition of the immune system, including immune organs, cells, and molecules. After that, we conclude the fundamental biological process of how a body generates humoral and cellular immune responses after recognizing antigens, hoping to gain a deeper understanding of the human body's immune system.