The present application provides novel human gene MICAL2-PV whose expression is markedly elevated in prostate cancers. Furthermore, it provides polypeptides encoded by the gene as well as polypeptides encoded by PCOTH which expression was also discovered to be elevated in prostate cancers. The genes and polypeptides encoded by the genes can be used, for example, in the diagnosis of prostate cancers, as target molecules for developing drugs against the disease, and for attenuating cell growth of prostate cancer.