The present invention relates to novel Fc variants that immuno-specifically bind to an Eph receptor. The Fc variants comprise a binding region that immunospecifically binds to an Eph receptor and an Fc region that further comprises at least one novel amino acid residue which may provide for enhanced effector function. More specifically, this invention provides Fc variants that have modified binding affinity to one or more Fc ligand (e.g., Fc.gamma.R, C1q). Additionally, the Fc variants have altered antibody-dependent cell-mediated cytotoxicity (ADCC) and/or complement dependent cytotoxicity (CDC) activity. The invention further provides methods and protocols for the application of said Fc variants that immunospecifically bind to an Eph receptor, particularly for therapeutic purposes.