To interrogate the molecular mechanism of PLZF, which has been demonstrated as a tumor-suppressor gene in human prostate cancer cells, and whether it is associated with the oncogenes JAK1, JAK2, and JAK3 as well as the TYK2(JAKs)–STAT signaling molecules, we ectopically transfected PLZF in DU145 cells. This evidence concerns the gene JAK3 and Familial prostate cancer.