Globulin is a serum protein that exists in the human body. Globulin is a common protein that basically exists in all animals and plants. Globulin has an immune function, so some people call it immunoglobulin. When the immune system encounters a foreign invader, it will produce different amounts of globulin depending on the invader. If the invader is difficult to eliminate, the immune system will stimulate the lymph and produce more globulin until the invader is eliminated by the globulin. .