Although loss of maspin expression was reported to correlate with increased aggression in advanced breast and prostate cancers, classifying maspin as a potent tumor suppressor, some in vivo studies characterized it as an important oncogene, as its overexpression was reported in cases of cancer of: pancreas, ovary, thyroid, lungs, and bladder [9,10,11,12]. The gene discussed is SERPINB5; the disease is Familial prostate cancer.