SFRP1 and hepatocellular carcinoma: To further evaluate the contribution of the down-regulation of SFRP1 to oncogenesis of HCC, two small interference RNAs (siRNAs), siRNA-SFRP1_888 for nt 888–909 and siRNA-SFRP1_1094 for 1094–1115 of SFRP1, were designed and chemically synthesized for the knockdown of SFRP1.