  We discuss the direct detection signatures of dark matter interacting with
nuclei via a Z' mediator, focussing on the case where both the dark matter and
the $Z'$ have mass of a few GeV. Isospin violation (i.e. different couplings to
protons and neutrons) arises naturally in this scenario. In particular it is
possible to reconcile the preferred parameter regions inferred from the
observed DAMA and CoGeNT modulations with the bounds from XENON100, which
requires f_n/f_p = -0.7. Moreover, the Z' mediator can also yield a large
spin-dependent cross-section which could contribute to the DAMA signal, while
the spin-independent cross-section is adequate to explain the CoGeNT signal.
