SFRP4 is physiologically expressed in the uterus, fallopian tubes and testis according to the Human Protein Atlas project [4], but aberrant expression and/or promoter methylation has been reported from many human cancer types including malignant mesotheliomas [5], ovarian- [6, 7], colon [8, 9], endometrial- [10], cervical- [11], bladder [12], pancreatic- [13] and other cancers (reviewed in [14, 15]). This evidence concerns the gene SFRP4 and cancer.