SFRP1 and colorectal carcinoma: Furthermore, we analyzed promoter methylation for additional genes that could play a similar tumor-suppressor role in CRC, including the mismatch repair gene Mlh1, the WNT signaling regulator Sfrp1, and the transcription factor Gata4. By comparing the changes of methylation among different promoters, we confirmed that the low dose DAC (0.5 μM) caused the most robust demethylation effect at the p16 promoter (Fig. S10).