DNMT1 and cancer: Analyses of Gene Ontology have revealed that genes related to chromatin/nucleosome assembly and organization, such as DNMT1, DNMT3A DNMT3B, UHRF1, and EZH2, are significantly enriched in human retinoblastoma compared to the normal retina, suggesting these epigenome regulators can be the targets for retinoblastoma and RB1-deficient cancers.