The present disclosure is directed to isolated or recombinant proteins, such as antibodies, which bind to, and inhibit or reduce the function of, midkine (MK) and their use as therapeutic and/or diagnostic agents for midkine-related disorders. The present disclosure is also related to nucleic acid sequences which encode said proteins and their expression in recombinant host cells. In particular, the present disclosure is directed towards humanized antibodies derived from murine antibody IP14 which specifically bind to human MK.
