  We explore the limits on lepton-flavor universality (LFU) violation in
theories where the hierarchy problem is solved by means of a warped extra
dimension. In those theories LFU violation, in fermion interaction with
Kaluza-Klein modes of gauge bosons, is provided ab initio when different flavor
of fermions are differently localized along the extra dimension. As this fact
arises from the mass pattern of quarks and leptons, LFU violation is natural in
this class of theories. We analyze the experimental data pointing towards LFU
violation, as well as the most relevant electroweak and flavor observables, and
the LFU tests in the $\mu/e$ and $\tau/\mu$ sectors. We find agreement with
$R_{K^{(\ast)}}$ and $R_{D^{(\ast)}}$ data at 95% CL, provided the third
generation left-handed fermions are composite ($0.14 < c_{b_L} < 0.28$ and
$0.27 < c_{\tau_L} < 0.33$), and find the absolute limits
$R_{K^{(\ast)}}\gtrsim 0.79$ and $R_{D^{(\ast)}}/R_{D^{(\ast)}}^{\rm
SM}\lesssim 1.13$. Moreover we predict $\mathcal B( B\to K\nu\bar\nu)\gtrsim
1.14\times 10^{-5}$ at 95% CL, smaller than the present experimental upper
bound but a few times larger than the Standard Model prediction.
