The invention provides antibodies or fragments thereof, including human antibodies, specific for Macrophage-Stimulating Protein Receptor (MSP-R or RON), which inhibit RON activation. Also provided are methods to inhibit RON, particularly the use of RON antibodies to treat diseases such as cancer.本發明提供對巨噬細胞刺激之蛋白質受體(MSP-R或RON)具有特異性、可抑制RON活化之抗體或其片段,包括人類抗體。亦提供抑制RON之方法,尤其RON抗體用於治療諸如癌症之疾病的用途。