From an operational definition of epigenetic, we move to provide the reader a general but comprehensive description of epigenetic phenomena that often lead to cell transformation. The last decade has, in fact, seen novel players involved in the regulation of gene expression. Not only protein factors but also a number of chromatin modifiers and remodelling proteins, which regulate the level of compaction of the genome through a variety of post-translational modifications deposed on histone tails or on DNA itself. Meanwhile, the discovery of tiny RNAs, of only 21-23 nucleotides in length, has brought to the attention their role as key regulators in the cell, being able to direct differentiation programs and function as oncogenes or oncosuppressors. In this general compendium, we aim to describe main cellular functions that through an epigenetic or epigenetic associated mechanism have been found to be directly implicated in cancerogenesis.