FOXO4 likely fulfills the currently accepted definition of a metastasis suppressor [41] in that it is downregulated in clinical metastases compared to primary-site CaP lesion, its downregulation correlates with significantly decreased time-to-onset of clinical metastasis, its expression levels do no grossly affect primary tumor growth, yet its downregulation promotes metastatic invasiveness in vitro and metastastic formation in vivo. Here, FOXO4 is linked to neoplasm.