Radiation fibrosis is a frequent sequel of therapeutic or accidental radiation overexposure in
normal human tissues. One of the main fundamental problems yet unsolved in fibrotic
tissues is the origin of the chronic activation of myofibroblasts within these tissues. It has
been postulated that this chronic activation results from a continuous production of activating
factors. In this context, fibrosis could be defined as a wound where continuous signals for
tissue repair are emitted. Cytokines and growth factors probably play a central role in this …