Although these findings make YAP1 a promising candidate for a useful clinical marker in prostate cancer, five validation studies applying immunohistochemistry to 20–188 prostate cancers reported inconclusive results: There was either reduced27,28, unchanged29 or up regulated5,30 YAP1 in tumours as compared to normal or benign prostate tissues. The gene discussed is YAP1; the disease is prostate cancer.