AB型 (Blood) is one of the four main blood types in the ABO blood group system, which also includes A型, B型, and O型. Individuals with AB型 blood have both A and B antigens on the surface of their red blood cells, making them universal recipients for blood transfusions. This means they can receive blood from any ABO type without experiencing an immune reaction. People with AB型 blood can produce antibodies against A型 and B型 blood, but not against their own antigens. This unique characteristic allows them to donate blood to other AB型 individuals, but they can only receive blood from A型, B型, AB型, and O型 donors.