In a previous attempt, our group studied the role of signal transducer and activator of transcription 3 (STAT3) in PCa, which turned out to exert tumor suppressor activities: Mice with a deletion of both Pten and Stat3 in the prostate epithelium develop aggressive metastatic tumors (Pencik et al, 2015). Here, STAT3 is linked to metastatic neoplasm.