Soluble frizzled-related proteins (sFRPS) function as modulators of Wnt signaling through direct interaction with Wnts. They have a role in regulating cell growth and differentiation in specific cell types. SFRP4 may act as a regulator of adult uterine morphology and function. Increases apoptosis during ovulation possibly through modulation of FZ1/FZ4/WNT4 signaling Has phosphaturic effects by specifically inhibiting sodium-dependent phosphate uptake. [SUBCELLULAR LOCATION] Secreted. Expressed in mesenchymal cells. Highly expressed in the stroma of proliferative endometrium. Expressed in cardiomyocytes. Belongs to the secreted frizzled-related protein (sFRP) family.