ID4 has been found to be epigenetically dysregulated in various cancer types: leukemia, AML, CLL, ALL, glial neoplasia, gastric cancer, pancreatic cancer, colorectal, lymphoma, cholangiocarcinoma, esophageal, lung and prostate cancers (Patel et al., 2015). Here, ID4 is linked to B-cell chronic lymphocytic leukemia.