The present invention concerns antigen binding proteins and fragments thereof which specifically bind Oncostatin M (OSM), particularly human OSM (hOSM) and which inhibit the binding of OSM to the gp130 receptor but does not directly interact with site II residues. The invention also concerns a method of humanising antibodies. Further disclosed are pharmaceutical compositions, screening and medical treatment methods.本發明係關於抗原結合蛋白質及其片段,其特異性結合抑瘤素M(OSM),尤其人類OSM(hOSM)且抑制OSM與gp130受體之結合但不直接與位點II處之殘基相互作用。本發明亦係關於人類化抗體之方法。此外揭示醫藥組合物、篩選及醫療方法。