TSPY (Testis specific protein, Y-encoded), a member of the greater SET (Su(var)3–9, Enhancer-of-zeste, Trithorax)/NAP (Nucleosome assembly protein) family of molecules, has been implicated in the regulation of gene expression, malignant development of gonadoblastoma and testicular and prostate cancer [59], [60]. The gene discussed is CTNNBL1; the disease is gonadoblastoma.