SFRP4 and neoplasm: Dhir et al. [17] carried out an analysis of methylation of Wnt signalling genes (APC1A, APC2, SFRP1, SFRP2, SFRP4, SFRP5, DKK1, DKK3, WIF1 and LKB1) in the development of UC associated neoplasia, finding that methylation of SFRP1/2 and APC1A/2 were associated with the progression to invasive disease.