This lecture covers the mechanisms of DNA methylation, focusing on CpG islands and the measurement techniques such as bisulphite modification. It also delves into histone modifications, including acetylation and methylation, and their impact on gene expression. The role of EZH2 oncogenic mutations in histone methylation and the interplay between microRNAs and cancer are discussed, along with the regulatory functions of proteins like CREBBP and EP300. The lecture concludes with an overview of genomic alterations affecting microRNAs and their implications in cancer.