New research is uncovering the role of epigenetics in programming fetal development, increasing susceptibility to acute and chronic disease. Development is a highly plastic process and any changes that occur during development due to environmental influences can be carried to future cells via alterations in epigenetic regulation of gene expression. These changes, functional in nature, may not appear until later in life leading to increased susceptibility to diseases. This session will focus on basic mechanisms that lead to altered developmental programming, mainly epigenetic changes. While this is a mechanistic basic session, it should have wide interest due to the widespread focus on developmental programming and later risk of diseases caused by a variety of environmental influences. It is likely that many if not all diseases have their origin during development.