Besides the fact that altered DNA methylation status changes gene expression and the overall cellular action, this is another example of how the two molecular processes of DNA methylation and cellular senescence are related. The next issue comes that mere regulation of post-transcriptional changes has the facts of DNA methylation and cellular senescence as a fundamental operation. Senescence is an example of autophagy, which is not completely related to cancer, meaning it can lead to a decrease in the number of abnormal epithelial cells alongside invasive carcinoma. The interplay between the DNA methylation process and cellular senescence tones down the mistakes of DNA methylation patterns created by genes and, thereby, leads to the formation of cells that are normotensive in behavior. The chapter delves into the influence of histone modifications and noncoding RNAs on the senescent phenotype, helping to illustrate the multifarious relationships between epigenetics and cell aging and diseases. Through a clear understanding of these mechanisms, we are able to find real solutions for the biological processes presented by aging and even target the molecular changes that result in the development of age-related conditions of the nervous system and cancer.