The fact that CCNJ is not expressed in normal HMEC cells but is expressed in certain cancer cells (MCF7 and MDA-MB-231) and that CCNJ silencing decreased the proliferation of MCF7 cells by inducing G2/M cell cycle arrest is consistent with the proliferative role of CCNJ suggested by other studies in Drosophila and prostate cancer cells [59,61]. This evidence concerns the gene CCNJ and Familial prostate cancer.