Epigenetics refers to DNA and chromatin modifications that persist from one cell division to the next despite a lack of change in the underlying DNA sequence. It is an emergent field since its implication in physiological and disease processes is now widely accepted. The effects of epigenetics play an important role in development but can also arise stochastically with ageing. Since their discovery in 1983, cancer-associated epigenetic changes have become accepted as playing a pivotal role in carcinogenesis, in conjunction with classical genomic mutations. Thus it is now well established that an epigenetic mechanism underlies the pathogenesis of cancer and there is evidence implicating epigenetic factors in the pathogenesis of idiopathic mental disorders such as schizophrenia, bipolar disorder and even autism. This new book gathers the latest research from around the globe in this field of study and related topics.