SFRP1 and hepatocellular carcinoma: In these HCC cell lines examined, the unmethylated CpG islands within SFRP1 promoter was found in Sk-Hep1 and Bel-7405 cells with the expression of SFRP1 via MSP, whereas the significant hypermethylation of the region occurred in Bel7402, SMMC7721, Bel7404, YY-8103, QGY7701, and MHCC-H cells without SFRP1 transcription.