RT Journal Article SR Electronic T1 Short history of 5-methylcytosine: from discovery to clinical applications JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP jclinpath-2020-206922 DO 10.1136/jclinpath-2020-206922 A1 Olga Taryma-Lesniak A1 Katarzyna Ewa Sokolowska A1 Tomasz Kazimierz Wojdacz YR 2021 UL http://jcp.bmj.com/content/early/2021/01/11/jclinpath-2020-206922.abstract AB Covalent modifications of nucleotides in genetic material have been known from the beginning of the last century. Currently, one of those modifications referred to as DNA methylation, is impacting personalised medicine both as a treatment target and a biomarker source for clinical disease management. In this short review, we describe landmark discoveries that led to the elucidation of the DNA methylation importance in the cell’s physiology and clarification of its role as one of the major processes in disease pathology. We also describe turning points in the development of methodologies to study this modification, which ultimately resulted in the development of in-vitro diagnostic kits targeting disease related DNA methylation changes as biomarkers.