Methods for improving the biological and pharmaceutical properties of bispecific binding agents are described herein where the bispecific binding agents are able to target cells by a high affinity binding domain to a first cell surface marker that does not induce a significant biological effect and a low affinity binding domain that binds specifically to a second cell surface marker, causing a significant and desired biological effect. Compositions of such bispecific binding agents, uses for them, and kits containing them are also provided.
