SO(5)xU(1) gauge-Higgs EW unification gives almost the same phenomenology as the standard model and is consistent with the data at low energies and at 8 TeV LHC. It gives many predictions to be explored and verified at 14 TeV LHC and 250-500 GeV ILC. In addition to the production of Z' bosons around 7 - 9 TeV with broad widths at 14 TeV LHC, distinct signals are predicted in future $e^+ e^-$ collider experiments with polarized beams. Significant deviations in the energy and polarization dependence in $\sigma(\mu^+\mu^-)$, the lepton forward-backward asymmetry, $R_b(\mu) \equiv \sigma(\bar{b}b)/\sigma(\mu^+\mu^-)$ and the left-right asymmetry from the standard model are predicted. (arXiv:1705.05282)