miR-21 promotes cell movement and invasion by targeting the mRNA of PTEN, a tumor suppressor protein [32], [36] miR-21 expression in PCa tissue samples was significantly associated with pathological stage, lymph node metastasis, capsularinvasion, organ-confined disease, Gleason score, biochemical recurrence, and patient follow-up. Here, PTEN is linked to metastatic malignant neoplasm in the lymph nodes.