DERL2 and colorectal cancer: DERL1 and DERL2 5′-end CpG island were unmethylated in all cases, but DERL3 CpG island promoter hypermethylation was found in four colorectal cancer cell lines: HCT-116, HCT-15, COLO-205 and SW48 (Fig. 1a and Supplementary Fig. 2).