  The measurement of nuclear Generalized Parton Distributions (GPDs) will
represent a valuable tool to understand the structure of bound nucleons in the
nuclear medium, as well as the role of non-nucleonic degrees of freedom in the
phenomenology of hard scattering off nuclei. By using a realistic microscopic
approach for the evaluation of GPDs of 3He, it will be shown that conventional
nuclear effects, such as isospin and binding ones, or the uncertainty related
to the use of a given nucleon-nucleon potential, are rather bigger than in the
forward case. These findings suggest that, if great attention is not paid to
infer the properties of nuclear GPDs from those of nuclear parton
distributions, conventional nuclear effects can be easily mistaken for exotic
ones. It is stressed therefore that 3He, for which the best realistic
calculations are possible, represents a unique target to discriminate between
conventional and exotic effects. The complementary information which could be
obtained by using a 3H target is also addressed.
