What is the function of surface antigens on RBCs?

Surface antigens on red blood cells (RBCs) play a crucial role in determining blood type and facilitating immune responses. These antigens, such as A, B, and Rh factors, are proteins and carbohydrates that help the immune system recognize self from non-self cells. When blood is transfused, the presence of incompatible antigens can trigger an immune reaction, leading to potentially serious complications. Additionally, these antigens are involved in various physiological processes, including cell signaling and adhesion.