SFRP4 and pituitary tumor: A review of 13 whole genome approaches in pituitary tumors with the goal of identifying Wnt family inhibitors showed that expression of WF1, SFRP2, FRZB, SFRP4, DKK2, and SOSTDC1 genes is decreased in pituitary adenomas compared to normal pituitary tissue, while that of SFRP1 and SFRP4 is increased [38].