SFRP2 and colorectal carcinoma: We previously showed that SFRP1, SFRP2 and SFRP5 are frequently inactivated in CRC and gastric cancer (GC) (Suzuki et al, 2002; Nojima et al, 2007), and that SFRPs suppress constitutive Wnt signalling when overexpressed in CRC and GC cells.