Disclosed are methods, compositions and kits for improving targeting, in particular tumor targeting, of immunoconjugates. The method and composition relies on the sequestration of non-target cells that also express the antigen the immunoconjugate targets. Sequestration of those non-target cells in a variety of ways is disclosed. The methods, compositions and kits allow appropriate sequestration of non-target cells while maintaining a high degree of effectiveness of the immunoconjugates against target cells.