The expression of hsa-miR-200b is upregulated in many malignant tumours [18–20], and its role in the inhibition of mesenchymal characteristics and metastasis has been revealed in prostate cancer, gastric carcinoma, and hepatocellular carcinoma via regulating ZEB1 expression or directly targeting ZEB2, or via Rho/ROCK signalling pathway [21–23]. The gene discussed is RHO; the disease is prostate cancer.