  The LHC data will provide sensitivity to an unification of the couplings at
low energies in the range $\sim$10-100 TeV. It is demonstrated in this note
that the lack of knowledge on the proton structure, specifically its gluon
distribution, can lower dramatically the sensitivity of bare cross section
measurements to this physics. However, some more elaborated strategies could
probably be developped to recover an important part of the sensitivity
