Secreted Frizzled Related Protein 4 (SFRP4)

Secreted frizzled-related protein 4 (SFRP4) is a member of the SFRP family that contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzled proteins. SFRPs act as soluble modulators of Wnt signaling. The expression of SFRP4 in ventricular myocardium correlates with apoptosis related gene expression.

Sequence analysis predicted that the 346-amino acid SFRP4 protein contains an N-terminal signal peptide, no transmembrane domain, and a hydrophilic C terminus. In situ hybridization analysis demonstrated exclusive expression in stromal and myometrial cells, particularly in endometrium and breast. Upregulated expression was detected in endometrial and breast carcinomas.