MiR-9-5p, a processing product of 5 prime of miR family member miR-9, also plays a role in promoting cancer or inhibiting cancer in many tumors, including cervical cancer, liver cancer [34], prostate cancer [35], breast cancer [36] and RCC [37] etc. Thrombospondin 2 (THBS2), a member of the calcium-binding glycoprotein family of stromal cells, is crucially involved in cell proliferation, adhesion and apoptosis. Here, THBS2 is linked to prostate cancer.