FOLH1 and metastatic neoplasm: Prostate-specific membrane antigen (PSMA) is an integral membrane protein, mapped to chromosome 11q14, which is over-expressed by a high number of prostate carcinomas; this expression is further increased in higher-grade carcinomas, in metastatic disease, and in hormone refractory prostate carcinomas, making it an interesting target for prostate carcinoma-specific imaging and therapy [1].