MST1R and cancer: Critical open questions requiring investigation to provide necessary preclinical data for translational studies include establishing the requirement of each pathway in RON-driven cancer phenotypes (tumor initiation, metastatic progression, etc.), pathway mechanisms linking RON receptor activation to changes in expression (e.g., downstream regulatory pathways leading to upregulation in transcription/translation), and preclinical efficacy testing of existing compounds that target these pathways (e.g., statins to target cholesterol biosynthesis).