  We review recent developments in leptogenesis on flavor effects. Their
account discloses an important connection between the matter-antimatter
asymmetry of the Universe and CP violation at low energies. Besides, they
modify the upper bound on the neutrino masses holding in the unflavored case.
In this respect, it is important to identify the exact condition for flavor
effects to be relevant and for the `fully flavored' Boltzmann equations to be
valid.
