MST1R and cancer: The tumor progression phenotypes caused by RON activation, such as cell adhesion, spreading, survival, migration, and epithelial-to-mesenchymal transition (EMT), are the result of activation of complex downstream signaling networks including the PI3K, MAPK, JNK, β-catenin, and STAT pathways.4,9 However, different cancers appear to rely on different signaling pathways downstream of RON.