Preferential binding to extratumoral IL-2 receptor-expressing cells has previously even been demonstrated for an i.v. injected tumor-targeted IL-2 antibody fusion protein and has been explained by the fact that the bispecific fusion protein encountered IL-2 receptor-positive cells earlier (e.g., in the blood) than tumor antigen-positive cells in the tumor [40]. Here, IL2 is linked to neoplasm.