anti-Secreted Frizzled-Related Protein 1 (SFRP1) (Internal Region) antibody: Anti-SFRP1 is a Stem Cell Antibody. SFRP1 (also known as FRP, FRP1, SARP2, Secreted Apoptosis-related Protein 2, Secreted Frizzled-related Protein and Secreted frizzled-related protein 1) 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. SFRP1 and SFRP5 may be involved in determining the polarity of photoreceptor cells in the retina. SFRP1 is expressed in several human tissues, with the highest levels in heart.