The present disclosure is directed to a modified isolated immunoglobulin CH2 domain that specifically binds to an extracellular region of an EphA2 receptor, wherein the amino acid sequence of the modified immunoglobulin CH2 domain includes at least one amino acid substitution, addition or deletion in comparison to a wild type immunoglobulin CH2 domain amino acid sequence, wherein the wild type immunoglobulin CH2 domain amino acid sequence includes SEQ ID NO:1 or SEQ ID NO:2. Heterologous immunoconjugates including fusion proteins and pharmaceutical compositions including the modified isolated immunoglobulin CH2 domain are also disclosed. In addition, methods of treating a disease associated with EphA2 overexpression and methods for killing a target cell expressing EphA2 receptors using the modified isolated immunoglobulin CH2 domain are provided.
