  Epigenetics has captured the attention of scientists in the past decades, yet
its scope has been continuously changing. In this paper, we give an overview on
how and why its definition has evolved and suggest several clarification on the
concepts used in this field, in particular, on the notions of epigenetic
information, epigenetic stability and epigenetic templating. Another issue that
we address is the role of epigenetic information. Not only it is important in
allowing alternative interpretations of genetic information, but it appears to
be important in protecting the genetic information, moreover, we suggest that
this function appeared first in evolution and only later on the epigenetic
mechanisms were recruited to play a role in cell differentiation.
