SFRP5 and colonic neoplasm: As shown in Fig. 1c, SFRP5 harbors a bivalent promoter in normal colon tissue, with both H3K27me3 and H3K4me3 signals, and devoid of H3K27ac; in comparison, SFRP5 becomes DNA hypermethylated, inaccessible (undetectable ATAC-Seq signal) and strongly repressed in colon cancer.