  The Higgs boson is in the backbone of the standard model of electroweak
interactions. It must exist in some form for achieving unification of
interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a
part of the extra-dimensional component of gauge fields. The Higgs boson
becomes absolutely stable in a class of the gauge-Higgs unification models,
serving as a promising candidate for cold dark matter in the universe. The
observed relic abundance of cold dark matter is obtained with the Higgs mass
around 70 GeV. The Higgs-nucleon scattering cross section is found to be close
to the recent CDMS II and XENON10 bounds in the direct detection of dark
matter. In collider experiments stable Higgs bosons are produced in a pair,
appearing as missing energies and momenta so that the way of detecting Higgs
bosons must be altered.
