For example, the CD47 antibodies of the invention are a significant improvement over an affinity-evolved SIRPa-Fc fusion protein that, when ให้ to mice and/or cynomolgus monkeys, caused red blood cell loss and anemia (See, Weiskopf et al. Engineered SIRPa Variants as Immunotherapeutic Adjuvants to Anticancer Antibodies. Science 2013; 341:88).