RBCs can be targets of infection directly or indirectly. When the microorganism enters the RBC directly, RBC damage becomes a fundamental aspect of the disease process. Malaria is the best example of an organism that directly targets the RBC, but others are Babesia and Bartonella. RBCs can also be indirect targets of infectious agents. This can occur when molecules are bound to the surface of the RBC, leading to immunologic clearance; when microorganismproduced toxins damage the RBC membrane, leading to hemolysis; when previous crypt-antigens are exposed, leading to accelerated removal; when microorganism-produced toxins alter RBC antigens to a different phenotype, or when microorganism suppression of erythropoiesis occurs due to specific binding to RBC precursors.