Munnes M, Patrone G, Schmitz B, Romeo G, Doerfler W. A 5'-CG-3'-rich region in the promoter of the transcriptionally frequently silenced RET protooncogene lacks methylated cytidine residues. Oncogene. 1998 Nov 19;17(20):2573–83. doi: 10.1038/sj.onc.1202165. PMID: 9840920.