  We discuss the behaviour of R(pA), the ratio of the unintegrated gluon
distribution of a nucleus over the unintegrated gluon distribution of a proton
scaled up by A^{1/3}, at high energy and fixed coupling. We show that R(pA)
exhibits a rising gluon shadowing with growing rapidity, approaching 1/A^{1/3}
at asymptotic rapidity, which means total gluon shadowing due to gluon number
fluctuations or Pomeron loops.
